Chandrian VS Code Color Theme

Chandrian is a semantic syntax highlighting theme, designed explicitly to make scanning large code-bases easier and to make errors more obvious. It features a 16-color palette with a mixture of carefully chosen warm, cold, and neutral colors. The colors are broadly categorized into:

• Warm Colors for action keywords - throw, return in programming languages, links in Markdown files.
• Cold colors for definitions - Function names, variable values etc.
• Muted neutral colors for punctuation, comments, and anything else which detracts from the code.

All colors have a contrast ratio of at least 4.5:1 and meet the criteria for "AA" accessibility level defined by the Web Content Accessibility Guidelines (WCAG).

Features

Programming languages

The colors for programming languages are designed to ease congnitive parsing of large blocks of code.

• Exit keywords (return/throw) and control keywords (if, for etc.) are assigned complementary warm colors bright enough to immediately catch your eye on a quick scan through.
• Function definitions / functional calls / property names are assigned complementary cold colors.
• Semi-colons, curly-braces etc are important for the compiler but are just visual noise for humans, and are hence shown in muted colors.
• Comments are important and helpful, but secondary to the actual code and are also muted.
• 'function', 'var', 'const' and other language keywords also toned down.
• Variable declarations are brighter than regular variables. I'm on the fence about if this helps or distracts (opinions welcome on Github issues); see notes below for instructions on turning this off.
• = is assigned a contrasting color to == so you can immediately catch if typo one for the other.

These rules should apply to most languages but were specifically designed for JS/Typescript. If something looks off in a particular language, issues/ PRs are welcome.

HTML

• Different colors for Block / Inline / Input elements / Web components.
• Classes are the most commonly used attribute and are shown more prominent than others, to help visually scan.
• href, form action attribute values, and inline event handlers are treated as action triggers and assigned brighter 'warm' colors.
• data- attributes are highlighted.
• Un-recognized tags show up brightly. Lifesaver if you chronically mistype 'form' as 'from' as I do.
• Errors, like say an extra angled < before an element are highlighted in red, as you can quickly see/scan from the screenshot.

CSS

• Different selector-types (element selectors / id selectors / attribute selectors/ pseduo-classes) are assigned different colors.
• Color definitions are shown in white. I recommend turning on VS Code's color preview so you can visually see the color next to its name.
• Mixins / variables / built-in functions are treated as actions and shown in warm colors.
• Vendor prefixes are 'noise' and are muted.
• Semicolons, colons etc. are all language noise and are muted.
• Known attribute values (relative / block etc.) are colored while unknown ones are not (position vs positon), to help catch typos.
• Known property-names (color / margin etc.) are colored while unknown ones are not, providing immediate feedback if you get it wrong.
• Obsolete properties are also shown as errors.

JSON

Common issues when working with large JSON files are:

1. Losing track of what level of nesting you're in, while parsing deeply-nested JSON.
2. Accidental trailing commas.
3. Missing a matching } somewhere.

This theme solves that by:

• Assigning each nested key-value pair is a different color combination, to help keep track of where you are (up to 5 levels. If you have to deal with structures deeper than that you have my sympathies).
• Making trailing commas visually more prominent.
• Using bright error colors to let you catch track down issues with malformed json.

Markdown

This theme is designed to enhance readability of Markdown documents and hence uses a minimum of colors in Markdown files.

• Header colors lighten for each heading level, to help you keep track of where you are.
• Italics are italicized, bolds are brighter.
• Links and code use warm colors
• De-emphasized urls minimize visual clutter.

VS Code Editor styling

Minimal changes has been made to the styling of VS Code itself, primarily:

• Changed the obnoxious blue of the activity bar to a more unobtrusive gray.
• Muted whitespace characters and other invisibles.

Misc. notes:

Theme variants / font suggestions

The default theme incorporates italics and works best with a font like Operator Mono / Danke Mono. There's also a non-italic variant for everything else - I recommend the excellent Source Code Pro.

How to turn off highlights for variable definitions

Add the following to your VS Code settings:

"editor.tokenColorCustomizations": {
    "[Chandrian Blue]": {
        "textMateRules": [{
            "scope": [
                "meta.definition.variable variable",
                "variable.other.constant"
            ],
            "settings": {
                "foreground": "#FFFFFFD4"
            }}]}}

Other misc. screenshots