# Color Theme Editor — Complete Guide

The Color Theme Editor is Fracturing Fog's modeless live-preview palette authoring tool. This guide covers every control, the persistence model, and 20 worked examples.

> Companion pages: [User Index](_Index.md) · [ColorGen DSL Guide](ColorGen-UserGuide.md)

![Color Theme Editor — new theme, Gradient kind selected.](../Images/dialogs/color-theme-editor.png)

---

## A friendly tour

The picture on screen is made of two layers stacked on top of each other:

1. **The fractal** — a black silhouette of points inside the set, surrounded by points outside it.
2. **The palette** — a paint-by-numbers rule that says "this number of escape steps ⇒ this colour".

The Theme Editor lets you edit that paint-by-numbers rule live, with the fractal repainting itself
as you drag sliders. Nothing you do here changes the math; it only changes how the math is
visualised.

### The three things worth understanding first

| Thing             | Plain meaning                                                                        |
|-------------------|---------------------------------------------------------------------------------------|
| **Colour Stops**  | A list of (position, colour) pairs. The picture fades between them in order.          |
| **Kind**          | Which colouring trick is applied: *Gradient*, *Cycling*, *Phong3D* (faux 3-D), *Pbr3D* (physically based). |
| **Live Preview**  | When the checkbox is ticked, edits appear in the main window within ~150 ms.          |

### Worked example — "Make my own sunset palette in two minutes"

1. Open Floating Menu → **Edit Theme…** (or press **`T`**).
2. Pick **Kind = Gradient**.
3. Empty the existing stop list and create four new stops:
   - position `0.00` — `#1A0040` (very dark purple)
   - position `0.40` — `#C42E1C` (deep orange-red)
   - position `0.75` — `#FFB347` (warm orange)
   - position `1.00` — `#FFF4B5` (pale yellow)
4. Tick **Live Preview**. The fractal repaints with the sunset.
5. Tweak each stop's position by dragging it left/right. Watch the colour zones grow / shrink.
6. Type a name (`Sunset over Mandelbrot`) and click **Save to Library**.
7. The new theme appears in the main *Theme* dropdown — you can pick it any time.

![Seahorse Valley at zoom 10³ painted with the "MS Standard Sunrise" gradient — warm amber filaments on cool blue voids.](../Images/examples/seahorse-sunset.png)

### Worked example — "Sample colours from a photo"

1. Click **From Image…** at the bottom of the editor.
2. Pick any JPG / PNG (an album cover, a landscape photo, a fabric swatch).
3. The Image Palette helper opens, samples the photo with k-means in CIELAB colour space, and
   gives you back five evenly-spaced stops.
4. Click **Use as Stops**. The Color Stops list is replaced.
5. Tick **Live Preview** — the fractal now wears the photo's palette.

> [!TIP]
> The Image Palette helper sorts stops by hue, then by lightness. If you want a *cooler* palette
> from a *warm* photo, swap stops 1↔5 and 2↔4 by dragging their position handles.

### Worked example — "Make the fractal look like polished metal"

1. Open the editor.
2. Switch **Kind = Pbr3D** (physically-based 3-D lighting).
3. **Steepness** = `1.5`. **Ambient** = `0.10`. **Glow exp** = `2.0`, **Glow scale** = `0.4`.
4. Material bands: a single entry with `metallic = 0.95`, `roughness = 0.15`.
5. Drag the **Key Light** direction so it falls roughly top-left. Set its **Diffuse RGB** to a
   warm white `#FFEBD0`.
6. Tick Live Preview. The fractal grows a metallic sheen with crisp specular highlights.

---

## Table of Contents

1. [Opening the Editor](#1-opening-the-editor)
2. [Layout](#2-layout)
3. [Identity Section](#3-identity-section)
4. [Kind Selector](#4-kind-selector)
5. [Color Stops](#5-color-stops)
6. [Randomize — Random Theme Generator](#6-randomize--random-theme-generator)
7. [Cycle Speed](#7-cycle-speed)
8. [3D Lighting (Phong + PBR)](#8-3d-lighting-phong--pbr)
9. [Phong3D Extras](#9-phong3d-extras)
10. [Pbr3D Extras](#10-pbr3d-extras)
11. [In-Set Color](#11-in-set-color)
12. [Post-FX Defaults](#12-post-fx-defaults)
13. [Live Preview + Actions](#13-live-preview--actions)
14. [Image Palette Helper](#14-image-palette-helper)
15. [JSON Schema](#15-json-schema)
16. [Worked Examples](#16-worked-examples)
17. [Tips + Troubleshooting](#17-tips--troubleshooting)

---

## 1. Opening the Editor

Three entry points:

- Toolbar **Edit Theme** button.
- Floating Menu → Color Themes → **Edit Theme…** button.
- Hotkey `T`.

The editor seeds from the currently-selected theme. Cancel-without-Save restores the previously active theme on close — your live preview edits don't pollute the library.

---

## 2. Layout

```
┌──────────────────────────────────────────────────────────────────┐
│ Target  : Region ▾   Base theme ▾                                │
│ Identity: Name __________  Kind ▾  Category ▾                    │
│           Description ___________  Max zoom _____                │
├──────────────────┬───────────────────────────────────────────────┤
│ Color Stops      │ 3D Lighting                                   │
│  Add 🎲Random    │  Steepness ___   Ambient ___                  │
│   From/Import/Exp │  Key   Dir XYZ  Diffuse RGB  Spec RGB  Shine  │
│  ☐Experim ☑In-set│  Fill  Dir XYZ  Diffuse RGB  Spec RGB  Shine  │
│   ☐Post-FX       │  ☐ Rim light                                  │
│   Seed ___ ☐Use  │                                               │
│      ☑Interp     │                                               │
│  ☐Inspect  ◎     │                                               │
│  [pos] [swatch]  │                                               │
│  [pos] [swatch]  │                                               │
│ Cycle            │ Phong3D extras                                │
│  Speed ___       │  Key/Fill/Rim  spec + diff scales             │
│                  │                                               │
│ In-Set           │ Pbr3D extras                                  │
│  ☐ Override RGBA │  Lighting mode ▾  Glow exp / scl              │
│                  │  Material bands [start end metal rough] …     │
│ Post-FX defaults │                                               │
│  Brightness ___  │                                               │
│  Contrast   ___  │                                               │
│  Adaptive   ___  │                                               │
│                  │                                               │
│ Actions          │                                               │
│  ☑ Live preview  │                                               │
│  [Apply] [Blank] │                                               │
│  [Revert]        │                                               │
│  [Save] [Export] │                                               │
│  [Save C#]       │                                               │
│  [From Image…]   │                                               │
└──────────────────┴───────────────────────────────────────────────┘
```

Sections collapse when irrelevant — Phong3D / PBR3D extras hide for Gradient + Cycling kinds.

---

## 3. Identity Section

| Field | Purpose |
|---|---|
| Name | Library key. Must be unique within `colorthemes.json`. |
| Kind | Gradient / Cycling / Phong3D / Pbr3D |
| Category | Free-form grouping label (used by the right-click sort menu) |
| Description | Optional free-text annotation |
| Max zoom | Optional metadata — UI does not enforce; future-proofing for adaptive theme switching |

**Save behavior:** if the typed Name already exists in the library, the editor prompts to confirm overwrite. Cancel returns to the editor with the existing entry untouched.

---

## 4. Kind Selector

| Kind | When to use |
|---|---|
| **Gradient** | Single-pass linear ramp across the iter range. Best for escape-time + distance-estimation maps where the iteration count is roughly monotonic. |
| **Cycling** | Repeats the gradient N times along the iter axis. Best for revealing fine band structure in shallow + medium zooms. |
| **Phong3D** | Cycling gradient + Blinn-Phong directional lighting computed from a synthesized surface normal (the Z component is built from the iter derivative). Gives a relief-mapped look. |
| **Pbr3D** | Cycling gradient + Cook-Torrance physically-based shading + per-band metallic/roughness. Gives a real-material look (chrome, brushed steel, ceramic, glass). |

Changing Kind shows / hides the relevant lighting sections.

---

## 5. Color Stops

| Control | Behavior |
|---|---|
| Position [0, 1] | Normalised stop along the gradient. 0 = low iter, 1 = high iter. |
| Swatch | Click for the color picker. RGB / hex entry below the swatch also works. |
| Add | Insert a new stop above the selected one. |
| Delete | Remove the selected stop. Editor enforces ≥ 2 stops. |
| Reorder | Drag the position handle to reposition. |

Stops interpolate linearly between adjacent positions. Outside [0, 1] the outer stops clamp.

**Tip:** for smooth gradients, space stops by perceptual distance, not numeric distance. Two close stops in dark regions look smoother than the same stops evenly placed across the full range.

---

## 6. Randomize — Random Theme Generator

The **🎲 Random** button (top of the Color Stops section) generates a complete theme in one click — not just the palette. It always builds a fresh set of colour stops via a golden-ratio hue walk (maximally-spaced hues so no two stops crowd the wheel), then layers on extra randomized settings chosen by the **current Kind** and by the toggle row directly beneath the button.

### What gets randomized

| Area | When |
|---|---|
| Colour stops | Always. |
| Interpolation (Space / Curve / Transfer / Strength / Gamma) | When **Interpolation** is ticked (default on). |
| Cycle settings (offset / density / speed / wrap mode) | Every Kind **except** Gradient. |
| 3D light rig + shared Steepness / Ambient | Phong3D and Pbr3D. |
| Phong extras (key/fill/rim spec + diff scales) | Phong3D only. |
| PBR lighting mode, glow, and material bands | Pbr3D only. |
| In-set (interior) colour | When **In-set** is ticked (default on). |
| Post-FX defaults (Brightness / Contrast / Adaptive-HE) | When **Post-FX** is ticked (default off). |

### The toggle row

| Control | Default | Effect |
|---|---|---|
| **Random Experimental** | off | Off = *artful* mode: every value stays inside a logical range, and 3D light colours + the in-set colour are pulled from the palette just generated so the result reads as one family. On = *experimental* mode: caps are removed and the generator "goes wild" — full-range colours, wider counts, unconstrained placement. |
| **In-set** | on | Include a random interior colour. Artful mode picks a dark member of the palette family (opaque) so the in-set reads as a recessed pocket; experimental mode allows any colour and any alpha. |
| **Post-FX** | off | Include random Post-FX defaults. Ticking this also ticks the Brightness / Contrast / Adaptive *Use* checkboxes to match (and unticking clears them) so you never have to flip them by hand. Artful mode keeps Brightness/Contrast within ±20 and Adaptive-HE under 50; experimental mode uses the full slider ranges. |
| **Interpolation** | on | Include random Space / Curve / Transfer / Transfer-strength / Palette-gamma. Artful keeps strength and gamma near neutral; experimental spans their full ranges. |

### Seed and reproducibility

- Every click records the seed used in the **Description** field and writes it into the **Seed** field.
- **Use Seed** (default off): while off, the Seed field is greyed out and each click draws a fresh seed — so repeated clicks keep producing new themes. Tick **Use Seed** to enable the field; the next click uses the value you enter.
- The same seed with the same toggles, Kind, and Experimental state reproduces an identical theme. A single seeded RNG drives every step in fixed order, so changing any of those inputs changes the result.

> [!TIP]
> Found a random theme you like? Its seed is already in the Seed field and the Description. Tick **Use Seed**, then flip **Random Experimental** on and off (or switch Kind) to explore controlled variations around the same starting point.

> [!NOTE]
> Randomize replaces the current stops and the settings it covers. Untick a scope toggle (In-set, Post-FX, Interpolation) to protect those sections from being overwritten.

---

## 7. Cycle Speed

Active for Cycling / Phong3D / Pbr3D kinds.

`Speed = 0.02` ≈ one full gradient cycle every 50 smoothed-iter units. Higher speed = more bands, tighter rings. Typical range 0.005 – 0.2.

For Phong3D + Pbr3D, the cycle controls the **base albedo** banding only — the lighting overlays on top, so a moderate cycle (0.02–0.05) usually reads better than a frantic high cycle.

---

## 8. 3D Lighting (Phong + PBR)

Shared parameters between Phong3D and Pbr3D kinds:

| Parameter | Purpose | Typical range |
|---|---|---:|
| Steepness | Z-scale on the synthesized normal. Higher = more relief depth. | 0.5 – 4.0 |
| Ambient | Base illumination before lighting. 0 = pitch-black shadows. | 0.0 – 0.3 |

### Lights

Each light carries:

| Field | Description |
|---|---|
| Direction (X, Y, Z) | Normalised direction vector. (0, 0, 1) = straight at camera. |
| Diffuse RGB | Color of the diffuse contribution. Bright key, dim fill is typical. |
| Specular RGB | Color of the highlight. White / warm for key, cool for fill. |
| Shininess | Specular exponent. 1 = matte, 256 = chrome. |

**Key Light** is the strong, often warm primary. **Fill Light** is the dim, often cool sim of sky / bounce. **Rim Light** (optional) is a back-light that highlights silhouette edges.

A balanced 3-point setup: Key 1.0 / Fill 0.4 / Rim 0.3.

---

## 9. Phong3D Extras

Phong3D exposes five per-light scale factors on top of the shared 3D-lighting block, letting you dial each light's diffuse / specular contribution independently for atmospheric accent (e.g., a cyan fill halo opposite the warm key spec).

| Field | Purpose | Typical range |
|---|---|---:|
| Key spec | Specular strength of the Key light. | 0.4 – 1.2 |
| Fill spec | Specular strength of the Fill light. | 0.1 – 0.5 |
| Fill diff | Diffuse strength of the Fill light. | 0.2 – 0.6 |
| Rim spec | Specular strength of the Rim light (only when Rim is enabled). | 0.5 – 1.5 |
| Rim diff | Diffuse strength of the Rim light (only when Rim is enabled). | 0.1 – 0.4 |

Leave them near their defaults for a balanced rig; push a single value when you want one light to dominate.

---

## 10. Pbr3D Extras

Pbr3D uses a Cook-Torrance BRDF with a GGX normal-distribution function and Smith geometric occlusion. Material parameters drive the BRDF:

| Field | Purpose | Range |
|---|---|---:|
| Lighting mode | `PBRRealistic` (filmic curve) / `PBRBright` (pre-multiplied radiance for a punchier sci-fi look) | enum |
| Glow exp / scale | Additive emission near escape (t → 1). | 0–10 / 0–5 |
| Material bands | List of `(start t, end t, metallic, roughness)` tuples. Lets you make the cardioid matte ceramic while the filaments turn chrome. | per-band |

Material bands are evaluated in declared order — the first band whose `(start, end)` contains the current t wins. Out-of-range t falls back to a default (metallic 0, roughness 0.5).

---

## 11. In-Set Color

When the **Override** checkbox is ticked, the picker sets the RGBA color for points that never escape (the cardioid + bulbs).

Default behavior (override off) draws the in-set with opaque black. Useful overrides:
- Dark navy `(8, 12, 32)` to keep contrast without harshness.
- Very-dark hue-matched color taken from the gradient's tail — keeps the in-set from popping visually.
- A partial alpha — the interior alpha **is** honored (per-theme, #96): below 255 the in-set composites over the 2D interior background, and the global `InteriorAlpha` knob multiplies this value. The swatch previews the authored alpha so a translucent interior reads as faded.

---

## 12. Post-FX Defaults

Per-theme defaults for the three Post-FX sliders.

When you select this theme from a combo, the renderer snaps each slider to the corresponding default — **unless** that slider's Lock checkbox is ticked. Locking lets you preserve a global brightness preference across theme browsing.

| Field | Range | Default |
|---|---:|---:|
| Brightness | −100 … +100 | 0 |
| Contrast | −100 … +100 | 0 |
| Adaptive | 0 … 100 | 0 |

---

## 13. Live Preview + Actions

| Action | Behavior |
|---|---|
| Live preview | Edits push to the main render via 150 ms debounce. Drag freely; the calculator re-runs once per debounced commit. |
| Apply | Force a push regardless of live-preview state. |
| New Blank | Discard edits; start from a fresh Gradient (2 stops, black → white). |
| Revert | Reload from the last source theme name. |
| Save to Library | Validate Name + ≥ 2 stops, upsert into `colorthemes.json`. Prompts to confirm overwrite if the name already exists. |
| Export JSON… | Write a single-theme JSON array to disk. |
| Save C#… | Write a compilable `ColorThemeData` C# class via `ColorThemeCsExporter`. Drop the file into `Models/ColorSchemes/Generated/` and rebuild to ship as built-in. |
| From Image… | Open the Image Palette helper. |

---

## 14. Image Palette Helper

Sample any PNG / JPG / BMP, get a 5-stop palette via k-means clustering in CIELAB color space, loaded straight into the Color Stops list.

| Control | Purpose |
|---|---|
| Source image | Click to browse. Loads + downsamples for analysis. |
| Cluster count | 2 – 16 centroids. Default 5. |
| Sort | By hue / by lightness / by frequency. |
| Sample bias | Center / Edges / Uniform — bias which pixels feed the kmeans. |
| Use as palette | Load the centroids as Color Stops. |

Tip: pick a source image whose mood matches your fractal target. A sunset photo for a warm Mandelbrot, a CT scan for a sci-fi Mandelbulb.

---

## 15. JSON Schema

Each entry in `colorthemes.json` is a single `ColorThemeData` object. Field omission follows `WhenWritingNull` — null fields disappear entirely.

```json
{
  "name": "My Theme",
  "kind": "Phong3D",
  "category": "Custom",
  "description": "Warm dusk shading",
  "maxZoom": 1e20,
  "stops": [
    { "position": 0.0, "r": 8,   "g": 4,   "b": 16  },
    { "position": 0.4, "r": 255, "g": 80,  "b": 16  },
    { "position": 1.0, "r": 255, "g": 230, "b": 180 }
  ],
  "cycleSpeed": 0.03,
  "lighting": {
    "steepness": 1.6,
    "ambient": 0.12,
    "keyLight": {
      "dir": { "x": 0.4, "y": 0.6, "z": 0.7 },
      "diffuse": { "r": 1.0, "g": 0.9, "b": 0.8 },
      "specular": { "r": 1.0, "g": 1.0, "b": 1.0 },
      "shininess": 64
    },
    "fillLight": { ... },
    "rim": null
  },
  "inSet": null,
  "postFxDefaults": {
    "brightness": 0,
    "contrast": 10,
    "adaptive": 0
  }
}
```

Pbr3D entries add a `pbrExtras` block with `lightingMode`, `glowExp`, `glowScale`, and a `materialBands` array.

**Colour options (optional, all kinds).** Omit for the historical look:

| Field | Values | Default | Effect |
|---|---|---|---|
| `interpolationSpace` | `Srgb` / `OkLab` / `Hsv` | `Srgb` | Colour space the gradient blends stops in. `OkLab` = perceptually smooth mid-tones; `Hsv` = shorter-arc hue sweep. Zero render cost (baked into the LUT). |
| `interpolationCurve` | `Linear` / `Cosine` / `Cubic` / `Step` | `Linear` | Segment blend shape. `Cosine` eases at both stops; `Cubic` = Catmull-Rom spline through stops (sRGB); `Step` = hard bands. |
| `transferFunction` | `Linear` / `Sqrt` / `Cubic` / `Log` / `Sine` | `Linear` | Remaps the mapping scalar before lookup (Ultra-Fractal "transfer"). `Log`/`Sqrt` spread deep detail; `Cubic` compresses shadows. Gradient + Cycling only. |
| `transferStrength` | float `[0,1]` | `1` | Blends identity↔`transferFunction`. |
| `paletteGamma` | float `[0.2,3]` | `1` | Per-theme gamma baked into the LUT (`out = in^(1/gamma)`). `>1` lifts shadows/brightens, `<1` darkens. Zero render cost; compounds with the live image-gamma slider. |
| `colorOffset` | float | `0` | Phase rotation of the palette along the iteration axis (Cycling / Phong3D / Pbr3D). |
| `colorDensity` | float | `1` | Frequency multiplier — how many cycles fit, independent of `cycleSpeed`. |
| `wrapMode` | `Repeat` / `PingPong` / `Clamp` | `Repeat` | Boundary behaviour. `PingPong` mirrors so there is no 1→0 seam. |

Each entry in `stops` also accepts an optional `midpoint` (float in (0,1),
default `0.5`): the blend midpoint of the segment *starting* at that stop.
Values below 0.5 push the halfway colour toward this stop, above 0.5 toward the
next. Omit (or `0.5`) for a straight blend.

---

## 16. Worked Examples

### Example 1 — Warm Sunset Gradient

- Kind: Gradient
- Stops: (0.0, #0A0613) → (0.3, #4B1B30) → (0.6, #C8521C) → (0.85, #FFA13C) → (1.0, #FFE9A8)
- In-set: override #050308.

### Example 2 — Cool Glacier Cycling

- Kind: Cycling
- Cycle Speed: 0.025
- Stops: (0.0, #050E2B) → (0.4, #1E5780) → (0.7, #C0E6FF) → (1.0, #FFFFFF)

### Example 3 — Twilight Spiral (3-stop)

- Kind: Cycling
- Cycle Speed: 0.04
- Stops: (0.0, #1A0033) → (0.5, #FF5599) → (1.0, #FFFF99)

### Example 4 — Solar Flare Phong3D

- Kind: Phong3D
- Cycle Speed: 0.03
- Stops: (0.0, #100000) → (0.45, #C04000) → (0.85, #FFC050) → (1.0, #FFFFE0)
- Steepness 2.2, Ambient 0.08
- Key Light dir (0.5, 0.6, 0.6), diffuse (1.0, 0.85, 0.55), spec (1.0, 1.0, 1.0), shine 96
- Fill Light dir (-0.4, -0.3, 0.5), diffuse (0.2, 0.3, 0.6), spec (0.4, 0.5, 0.8), shine 32

### Example 5 — Brushed Copper Pbr3D

- Kind: Pbr3D
- Cycle Speed: 0.02
- Stops: (0.0, #110804) → (0.5, #C57033) → (1.0, #FFD79A)
- Lighting mode: PBRRealistic
- Material bands: [(0.0, 0.5, metallic 1.0, roughness 0.4), (0.5, 1.0, metallic 1.0, roughness 0.18)]
- Glow exp 6.0, scale 0.4

### Example 6 — Chrome Filament

- Kind: Pbr3D
- Stops: (0.0, #050505) → (1.0, #FFFFFF)
- Material bands: [(0.0, 1.0, metallic 1.0, roughness 0.05)]

### Example 7 — Domain Coloring Argument

- Kind: Gradient with HSV-cycling color stops (12 stops around the hue wheel)
- In-set: override #000000.

### Example 8 — Phosphor CRT

- Stops: (0.0, #000000) → (0.5, #003B00) → (1.0, #6CFFB1)
- Post-FX defaults: contrast +20, brightness -10.

### Example 9 — Bauhaus Primary

- Kind: Cycling
- Cycle Speed: 0.05
- Stops: (0.0, #E63946) → (0.5, #F1FA8C) → (1.0, #1D3557)

### Example 10 — Inferno-style

- Stops: (0.0, #000004) → (0.25, #420A68) → (0.5, #932667) → (0.75, #DD513A) → (1.0, #FCFFA4)

### Example 11 — Pastel Cotton Candy

- Stops: (0.0, #FFC4D6) → (0.5, #C4B5FF) → (1.0, #B8F0FF)
- Cycle Speed: 0.03

### Example 12 — Topo Map

- Kind: Cycling
- Cycle Speed: 0.08
- Stops: (0.0, #2E512E) → (0.4, #5A8C39) → (0.7, #C9B780) → (1.0, #FFFFFF)
- Repeats every ~12 iter units; reads like elevation rings.

### Example 13 — Iridescent Oil Slick

- Kind: Cycling
- Cycle Speed: 0.06
- Stops: 6 stops cycling through magenta → blue → green → yellow → red → magenta.

### Example 14 — Tron Grid

- Kind: Pbr3D
- Stops: (0.0, #00111A) → (0.5, #00B0E0) → (1.0, #80FFFF)
- Material bands: [(0.0, 1.0, metallic 0.6, roughness 0.25)]
- Glow exp 4.0, scale 1.2

### Example 15 — Vintage Sepia

- Stops: (0.0, #2A1505) → (0.6, #A07550) → (1.0, #F0E0C0)
- Post-FX defaults: contrast +5.

### Example 16 — Ice Cave

- Kind: Phong3D
- Cycle Speed: 0.025
- Stops: (0.0, #051F3B) → (0.5, #7EB5E0) → (1.0, #FFFFFF)
- Steepness 1.8, Ambient 0.15

### Example 17 — Volcanic Glass

- Kind: Pbr3D
- Stops: (0.0, #050505) → (0.7, #4B0010) → (1.0, #FF7050)
- Material bands: [(0.0, 0.7, metallic 0.0, roughness 0.6), (0.7, 1.0, metallic 0.0, roughness 0.05)]
- Glow exp 3.0, scale 0.8

### Example 18 — Watercolor

- Stops: (0.0, #F4E9DC) → (0.5, #B8D8E5) → (1.0, #D4A5A5)
- Post-FX defaults: brightness +10.

### Example 19 — Ultra-Violet

- Kind: Cycling
- Cycle Speed: 0.07
- Stops: 4 stops (#000033 → #6633CC → #CC33FF → #FFFFFF) repeated.
- Pair with Adaptive = 80 for psychedelic deep-zooms.

### Example 20 — Mono Ink

- Stops: (0.0, #FFFFFF) → (0.5, #777777) → (1.0, #000000)
- Cycle Speed: 0.04
- Useful for distance-estimation maps where shape, not color, is the goal.

---

## 17. Tips + Troubleshooting

**Live preview lagging.** Lower Cycle Speed temporarily, or untick Live preview and use Apply between edits.

**Banding visible at deep zoom.** Increase iteration count (Floating Menu → Iter), or raise Quality. The palette only colors what the calculator computes; bands appear when iter is too low for the depth.

**Phong3D looks plastic.** Drop Specular RGB and raise Roughness — actually, switch to Pbr3D and use the material band system. Phong's specular model lacks the energy conservation that makes PBR materials look ""real.""

**Pbr3D too dark.** Raise Ambient to 0.15–0.2, switch Lighting mode to PBRBright, or push the glow scale.

**In-set color washes out the rest.** Untick the override; the default opaque-black tends to read better. If you must override, pick a desaturated low-luma color.

**Save button silently overwrites.** As of v0.6.2, the overwrite confirmation prompt prevents accidental clobbering. If you're not seeing the prompt, the typed name doesn't match any existing user theme — Save proceeds as an insert.

**My theme disappears after reload.** Built-in themes don't write to `colorthemes.json`; only user-saved themes do. Use Save to Library, not Export JSON, for persistence.

**Image Palette returns washed-out colors.** Bias toward Edges or pick a more saturated source image. K-means clusters in CIELAB; pure-grey source images give a grey palette.

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*Color Theme Editor Guide · Fracturing Fog · © 2026*