diff --git a/apps/obsidian/src/components/RelationshipTypeSettings.tsx b/apps/obsidian/src/components/RelationshipTypeSettings.tsx
index 24a20ecf3..9157f551c 100644
--- a/apps/obsidian/src/components/RelationshipTypeSettings.tsx
+++ b/apps/obsidian/src/components/RelationshipTypeSettings.tsx
@@ -1,9 +1,112 @@
-import { useState } from "react";
+import { useState, useRef, useEffect } from "react";
 import { DiscourseRelationType } from "~/types";
 import { Notice } from "obsidian";
 import { usePlugin } from "./PluginContext";
 import generateUid from "~/utils/generateUid";
 import { ConfirmationModal } from "./ConfirmationModal";
+import {
+  TLDRAW_COLOR_NAMES,
+  TLDRAW_COLOR_LABELS,
+  DEFAULT_TLDRAW_COLOR,
+  COLOR_PALETTE,
+  type TldrawColorName,
+} from "~/utils/tldrawColors";
+import { getContrastColor } from "~/utils/colorUtils";
+
+type ColorPickerProps = {
+  value: string;
+  onChange: (color: TldrawColorName) => void;
+};
+
+const ColorPicker = ({ value, onChange }: ColorPickerProps) => {
+  const [isOpen, setIsOpen] = useState(false);
+  const dropdownRef = useRef<HTMLDivElement>(null);
+
+  useEffect(() => {
+    const handleClickOutside = (event: MouseEvent) => {
+      if (
+        dropdownRef.current &&
+        !dropdownRef.current.contains(event.target as Node)
+      ) {
+        setIsOpen(false);
+      }
+    };
+
+    if (isOpen) {
+      document.addEventListener("mousedown", handleClickOutside);
+      return () => {
+        document.removeEventListener("mousedown", handleClickOutside);
+      };
+    }
+  }, [isOpen]);
+
+  const currentColor = value as TldrawColorName;
+  const bgColor = COLOR_PALETTE[currentColor] ?? COLOR_PALETTE.black;
+  const textColor = getContrastColor(bgColor ?? DEFAULT_TLDRAW_COLOR);
+
+  return (
+    <div ref={dropdownRef} className="relative" style={{ minWidth: "140px" }}>
+      <button
+        type="button"
+        onClick={() => setIsOpen(!isOpen)}
+        className="flex w-full items-center justify-between rounded border px-3 py-2 text-left"
+        style={{
+          backgroundColor: bgColor,
+          color: textColor,
+        }}
+      >
+        <span className="flex items-center gap-2">
+          <span
+            className="inline-block rounded-full"
+            style={{
+              width: "12px",
+              height: "12px",
+              backgroundColor: bgColor,
+              border: `2px solid ${textColor}`,
+            }}
+          />
+          {TLDRAW_COLOR_LABELS[currentColor]}
+        </span>
+        <span style={{ fontSize: "10px" }}>{isOpen ? "▲" : "▼"}</span>
+      </button>
+
+      {isOpen && (
+        <div
+          className="absolute z-50 mt-1 w-full"
+          style={{
+            maxHeight: "300px",
+            overflowY: "auto",
+          }}
+        >
+          {TLDRAW_COLOR_NAMES.map((colorName) => {
+            const bgColor = COLOR_PALETTE[colorName] ?? COLOR_PALETTE.black;
+            return (
+              <button
+                key={colorName}
+                type="button"
+                onClick={() => {
+                  onChange(colorName);
+                  setIsOpen(false);
+                }}
+                className="flex w-full flex-row justify-start gap-2 rounded-none px-3 py-2"
+              >
+                <span
+                  className="inline-block rounded-full"
+                  style={{
+                    width: "12px",
+                    height: "12px",
+                    backgroundColor: bgColor,
+                  }}
+                />
+                {TLDRAW_COLOR_LABELS[colorName]}
+              </button>
+            );
+          })}
+        </div>
+      )}
+    </div>
+  );
+};
 
 const RelationshipTypeSettings = () => {
   const plugin = usePlugin();
@@ -24,11 +127,14 @@ const RelationshipTypeSettings = () => {
         id: newId,
         label: "",
         complement: "",
-        color: "#000000",
+        color: DEFAULT_TLDRAW_COLOR,
       };
     }
-
-    updatedRelationTypes[index][field] = value;
+    if (field === "color") {
+      updatedRelationTypes[index].color = value as TldrawColorName;
+    } else {
+      updatedRelationTypes[index][field] = value;
+    }
     setRelationTypes(updatedRelationTypes);
     setHasUnsavedChanges(true);
   };
@@ -42,7 +148,7 @@ const RelationshipTypeSettings = () => {
         id: newId,
         label: "",
         complement: "",
-        color: "#000000",
+        color: DEFAULT_TLDRAW_COLOR,
       },
     ];
     setRelationTypes(updatedRelationTypes);
@@ -53,7 +159,7 @@ const RelationshipTypeSettings = () => {
     const relationType = relationTypes[index] || {
       label: "Unnamed",
       complement: "",
-      color: "#000000",
+      color: DEFAULT_TLDRAW_COLOR,
     };
     const modal = new ConfirmationModal(plugin.app, {
       title: "Delete Relation Type",
@@ -84,7 +190,7 @@ const RelationshipTypeSettings = () => {
 
   const handleSave = async (): Promise<void> => {
     for (const relType of relationTypes) {
-      if (!relType.id || !relType.label || !relType.complement || !relType.color) {
+      if (!relType.id || !relType.label || !relType.complement) {
         new Notice("All fields are required for relation types.");
         return;
       }
@@ -132,14 +238,11 @@ const RelationshipTypeSettings = () => {
                 }
                 className="flex-1"
               />
-              <input
-                type="color"
+              <ColorPicker
                 value={relationType.color}
-                onChange={(e) =>
-                  handleRelationTypeChange(index, "color", e.target.value)
+                onChange={(color) =>
+                  handleRelationTypeChange(index, "color", color)
                 }
-                className="w-12 h-8 rounded border"
-                title="Relation color"
               />
               <button
                 onClick={() => confirmDeleteRelationType(index)}
diff --git a/apps/obsidian/src/components/canvas/DiscourseRelationTool.ts b/apps/obsidian/src/components/canvas/DiscourseRelationTool.ts
index 50afe423f..f807127a8 100644
--- a/apps/obsidian/src/components/canvas/DiscourseRelationTool.ts
+++ b/apps/obsidian/src/components/canvas/DiscourseRelationTool.ts
@@ -6,6 +6,7 @@ import { getRelationTypeById } from "~/utils/typeUtils";
 import { DiscourseRelationShape } from "./shapes/DiscourseRelationShape";
 import { getNodeTypeById } from "~/utils/typeUtils";
 import { showToast } from "./utils/toastUtils";
+import { DEFAULT_TLDRAW_COLOR } from "~/utils/tldrawColors";
 
 type RelationToolContext = {
   plugin: DiscourseGraphPlugin;
@@ -250,6 +251,7 @@ class Pointing extends StateNode {
       props: {
         relationTypeId: relationToolContext.relationTypeId,
         text: relationType?.label ?? "",
+        color: relationType?.color ?? DEFAULT_TLDRAW_COLOR,
         scale: this.editor.user.getIsDynamicResizeMode()
           ? 1 / this.editor.getZoomLevel()
           : 1,
diff --git a/apps/obsidian/src/components/canvas/overlays/RelationPanel.tsx b/apps/obsidian/src/components/canvas/overlays/RelationPanel.tsx
index 9da3ba00a..fe59fd5ab 100644
--- a/apps/obsidian/src/components/canvas/overlays/RelationPanel.tsx
+++ b/apps/obsidian/src/components/canvas/overlays/RelationPanel.tsx
@@ -16,6 +16,7 @@ import {
 import { getFrontmatterForFile } from "~/components/canvas/shapes/discourseNodeShapeUtils";
 import { getRelationTypeById } from "~/utils/typeUtils";
 import { showToast } from "~/components/canvas/utils/toastUtils";
+import { DEFAULT_TLDRAW_COLOR } from "~/utils/tldrawColors";
 
 type GroupedRelation = {
   key: string;
@@ -377,7 +378,7 @@ export const RelationsPanel = ({
           dash: "draw",
           size: "m",
           fill: "none",
-          color: "black",
+          color: relationType?.color ?? DEFAULT_TLDRAW_COLOR,
           labelColor: "black",
           bend: 0,
           // Will be updated by bindings
diff --git a/apps/obsidian/src/components/canvas/utils/relationUtils.tsx b/apps/obsidian/src/components/canvas/utils/relationUtils.tsx
index 82fef8ffa..51b950997 100644
--- a/apps/obsidian/src/components/canvas/utils/relationUtils.tsx
+++ b/apps/obsidian/src/components/canvas/utils/relationUtils.tsx
@@ -67,6 +67,7 @@ import {
   TLDefaultSizeStyle,
   PI2,
   TLArcInfo,
+  TLDefaultColorThemeColor,
 } from "tldraw";
 import type {
   RelationBindings,
@@ -77,6 +78,7 @@ import {
   DiscourseRelationShape,
   DiscourseRelationUtil,
 } from "~/components/canvas/shapes/DiscourseRelationShape";
+import { DEFAULT_TLDRAW_COLOR } from "~/utils/tldrawColors";
 
 let defaultPixels: { white: string; black: string } | null = null;
 let globalRenderIndex = 0;
@@ -1872,11 +1874,18 @@ export const ArrowSvg = track(function ArrowSvg({
   // color: string;
 }) {
   const editor = useEditor();
-  // const theme = useDefaultColorTheme();
+  const theme = useDefaultColorTheme();
   const info = getArrowInfo(editor, shape);
   const bounds = Box.ZeroFix(editor.getShapeGeometry(shape).bounds);
   const bindings = getArrowBindings(editor, shape);
 
+  // Ensure color is a valid tldraw color name, fallback to black if not
+  const colorName =
+    shape.props.color && theme[shape.props.color as keyof typeof theme]
+      ? (shape.props.color as keyof typeof theme)
+      : DEFAULT_TLDRAW_COLOR;
+  const colorHex = (theme[colorName] as TLDefaultColorThemeColor).solid;
+
   const changeIndex = React.useMemo<number>(() => {
     return editor.environment.isSafari ? (globalRenderIndex += 1) : 0;
     // eslint-disable-next-line react-hooks/exhaustive-deps
@@ -2006,7 +2015,7 @@ export const ArrowSvg = track(function ArrowSvg({
       </defs>
       <g
         fill="none"
-        stroke={shape.props.color}
+        stroke={colorHex}
         strokeWidth={strokeWidth}
         strokeLinejoin="round"
         strokeLinecap="round"
@@ -2030,18 +2039,18 @@ export const ArrowSvg = track(function ArrowSvg({
         </g>
         {as && maskStartArrowhead && shape.props.fill !== "none" && (
           <ShapeFill
-            // theme={theme}
+            theme={theme}
             d={as}
-            color={shape.props.color}
+            color={colorHex}
             fill={shape.props.fill}
             scale={shape.props.scale}
           />
         )}
         {ae && maskEndArrowhead && shape.props.fill !== "none" && (
           <ShapeFill
-            // theme={theme}
+            theme={theme}
             d={ae}
-            color={shape.props.color}
+            color={colorHex}
             fill={shape.props.fill}
             scale={shape.props.scale}
           />
diff --git a/apps/obsidian/src/constants.ts b/apps/obsidian/src/constants.ts
index 1d6cc9781..7ac6f0d8e 100644
--- a/apps/obsidian/src/constants.ts
+++ b/apps/obsidian/src/constants.ts
@@ -28,19 +28,19 @@ export const DEFAULT_RELATION_TYPES: Record<string, DiscourseRelationType> = {
     id: generateUid("relation"),
     label: "supports",
     complement: "is supported by",
-    color: "#099268",
+    color: "green",
   },
   opposes: {
     id: generateUid("relation"),
     label: "opposes",
     complement: "is opposed by",
-    color: "#e03131",
+    color: "red",
   },
   informs: {
     id: generateUid("relation"),
     label: "informs",
     complement: "is informed by",
-    color: "#adb5bd",
+    color: "grey",
   },
 };
 
diff --git a/apps/obsidian/src/types.ts b/apps/obsidian/src/types.ts
index fc0055592..73c273bd3 100644
--- a/apps/obsidian/src/types.ts
+++ b/apps/obsidian/src/types.ts
@@ -1,4 +1,5 @@
 import { TFile } from "obsidian";
+import { TldrawColorName } from "./utils/tldrawColors";
 
 export type DiscourseNode = {
   id: string;
@@ -16,7 +17,7 @@ export type DiscourseRelationType = {
   id: string;
   label: string;
   complement: string;
-  color: string;
+  color: TldrawColorName;
 };
 
 export type DiscourseRelation = {
diff --git a/apps/obsidian/src/utils/tldrawColors.ts b/apps/obsidian/src/utils/tldrawColors.ts
new file mode 100644
index 000000000..a4b3583f7
--- /dev/null
+++ b/apps/obsidian/src/utils/tldrawColors.ts
@@ -0,0 +1,60 @@
+/**
+ * Tldraw color names that can be used for relation types.
+ * These match the defaultColorNames from tldraw's TLColorStyle.
+ */
+export const TLDRAW_COLOR_NAMES = [
+  "black",
+  "grey",
+  "light-violet",
+  "violet",
+  "blue",
+  "light-blue",
+  "yellow",
+  "orange",
+  "green",
+  "light-green",
+  "light-red",
+  "red",
+  "white",
+] as const;
+
+export type TldrawColorName = (typeof TLDRAW_COLOR_NAMES)[number];
+
+/**
+ * Human-readable labels for tldraw color names
+ */
+export const TLDRAW_COLOR_LABELS: Record<TldrawColorName, string> = {
+  black: "Black",
+  grey: "Grey",
+  "light-violet": "Light Violet",
+  violet: "Violet",
+  blue: "Blue",
+  "light-blue": "Light Blue",
+  yellow: "Yellow",
+  orange: "Orange",
+  green: "Green",
+  "light-green": "Light Green",
+  "light-red": "Light Red",
+  red: "Red",
+  white: "White",
+};
+
+export const DEFAULT_TLDRAW_COLOR: TldrawColorName = "black";
+
+// from @tldraw/editor/editor.css
+/* eslint-disable @typescript-eslint/naming-convention */
+export const COLOR_PALETTE: Record<string, string> = {
+  black: "#1d1d1d",
+  blue: "#4263eb",
+  green: "#099268",
+  grey: "#adb5bd",
+  "light-blue": "#4dabf7",
+  "light-green": "#40c057",
+  "light-red": "#ff8787",
+  "light-violet": "#e599f7",
+  orange: "#f76707",
+  red: "#e03131",
+  violet: "#ae3ec9",
+  white: "#ffffff",
+  yellow: "#ffc078",
+};