Your editor, tuned to your eyes.
Irish: dath — colour
Dath is a visual comfort layer that sits on top of any VS Code theme you already use. It does not replace your theme — it corrects it.
For developers with colour vision deficiency (CVD), the problem isn't that themes are badly designed — it's that they're designed for trichromat vision. Red strings and green comments look identical to a deuteranope. Dath shifts those specific colour ranges to safe alternatives while preserving the character of your theme.
For everyone else, Dath addresses the broader comfort problems that themes don't solve: harsh white backgrounds, snow blindness, visual noise, and the friction of font and spacing settings buried in JSON.
Everything is non-destructive. Dath writes only to VS Code's workbench.colorCustomizations override layer — never your theme files. Disable it and your editor is exactly as it was.
Applies LMS daltonization (Brettel, Viénot & Mollon, 1997) to your active theme's colours. Reads the theme JSON directly from disk and corrects both workbench UI tokens and TextMate syntax token colours.
| Mode | Cone affected | Most common in |
|---|---|---|
| Deuteranopia | M (green) | ~6% of males |
| Protanopia | L (red) | ~2% of males |
| Tritanopia | S (blue) | ~0.01% of population |
| Achromatopsia | All cones | Rod monochromacy — luminance only |
A severity slider (0.1–1.0) lets you dial in the correction strength — 1.0 for complete CVD, lower for partial deficiency.
Simulate mode — instead of correcting, show what your current theme looks like to someone with the selected CVD type. Useful for theme authors and for demonstrating CVD to colleagues.
Custom palette slots (Custom 1, 2, 3) let you define your own per-role colour overrides directly in the panel using colour pickers.
| Mode | Effect |
|---|---|
| Soften | Lifts pure whites toward a warm off-white — reduces snow blindness |
| Warm | Warms the background tone |
| Cool | Cools the background tone |
| Dim | Reduces overall brightness |
A temperature bias slider lets you add a persistent warm or cool hue tint on top of all other corrections.
CVD-safe bracket palettes derived from the Wong (2011) colour palette — distinguishable under all CVD types. The palette updates automatically to match your active CVD mode.
Shape hints add a subtle underline to matching bracket pairs so they are identifiable without relying on colour alone.
Rainbow indent guides colour VS Code's indent guide lines to match the bracket palette, giving an additional spatial cue for nested code structure.
Override editor typography without editing settings.json manually:
- Font family — quick picks for OpenDyslexic, Atkinson Hyperlegible, and Lexie Readable, or type any font installed on your system
- Font size — px override (0 = VS Code default)
- Line height — override for improved readability (suggested 1.4–1.8)
- Letter spacing — px override
Named configurations that switch in one click. Save, rename, delete, export, and import profiles from the panel or command palette. Three built-in starters are included on first install:
| Profile | Description |
|---|---|
| Deuteranopia | Full deuteranopia correction, softened backgrounds, CVD-safe brackets |
| Protanopia | Full protanopia correction, CVD-safe brackets |
| Dyslexia Comfort | Softened contrast, Atkinson Hyperlegible font, increased line height |
Auto dark/light switching — set dath.darkModeProfile and dath.lightModeProfile to automatically apply the right profile when VS Code (or the OS) switches between dark and light mode.
Click the status bar item to open the Dath panel — a live interactive control surface. Changes apply immediately as you adjust sliders or click mode buttons.
- Per-section reset buttons restore individual sections to defaults
- Global reset restores all Dath settings at once
- Live colour correction preview shows before/after swatches for representative theme colours
- Bracket palette preview updates in real time
- Profile management — apply, save, rename, delete, export, and import profiles without leaving the panel
- Simulate toggle — preview what your theme looks like to a CVD user
- Status bar shows a warning indicator if the theme file could not be read
- On activation, Dath reads your active theme's JSON file from disk (including JSONC comment stripping and
includechain resolution) - It applies the LMS daltonization pipeline to workbench colour tokens, TextMate syntax scopes, and semantic token colours
- Corrected values are written to
workbench.colorCustomizations,editor.tokenColorCustomizations, andeditor.semanticTokenColorCustomizationsin your global settings - When you disable Dath or change settings, only Dath's entries are removed — your own customisations are preserved
Dath manages 185 workbench colour tokens spanning the editor, sidebar, tabs, terminal, diff view, and more. It also reads and corrects semanticTokenColors from the theme file, covering the semantic highlighting layer used by modern themes alongside TextMate scopes.
- Install from the VS Code Marketplace
- The setup wizard runs automatically on first install — choose your CVD type, contrast preference, and bracket options
- Click the
$(eye) Dathitem in the status bar to open the panel at any time - Or: Ctrl+Alt+D / Cmd+Alt+D — or Ctrl/Cmd+Shift+P →
Dath: Open Panel
Dath uses only standard VS Code extension APIs and works in any VS Code-compatible editor — Cursor, Windsurf, Gitpod, Project IDX, and others — without any changes.
VSCodium users: VSCodium does not use the VS Code Marketplace. Install via the .vsix file from the GitHub releases page, or find Dath on open-vsx.org if it has been published there.
| Command | Description |
|---|---|
Dath: Open Panel | Open the visual control panel |
Dath: Toggle On/Off | Enable or disable all corrections |
Dath: Switch Profile | Switch to a saved profile |
Dath: Save Current Settings as Profile | Save current config as a named profile |
Dath: Open Settings | Jump to Dath settings in the VS Code settings UI |
Dath: Run Setup Wizard | Run the onboarding wizard again |
Dath: Export Profiles to Clipboard | Copy all saved profiles as JSON |
Dath: Import Profiles from Clipboard | Import profiles from clipboard JSON |
Dath: Rename Profile | Rename a saved profile |
Dath: Delete Profile | Delete a saved profile |
| Setting | Default | Description |
|---|---|---|
dath.enabled | true | Enable or disable all corrections |
dath.cvdMode | none | CVD correction: none · deuteranopia · protanopia · tritanopia · achromatopsia · custom1 · custom2 · custom3 |
dath.cvdSeverity | 1.0 | Correction strength 0.1–1.0 (ignored for custom and achromatopsia modes) |
dath.simulationMode | false | Show how the theme looks to a CVD user rather than correcting it |
dath.contrastMode | none | Background adjustment: none · soften · warm · cool · dim |
dath.contrastStrength | 0.5 | Contrast adjustment strength 0.1–1.0 |
dath.warmthBias | 0 | Hue tint: positive = warm, negative = cool, 0 = neutral |
dath.rainbowBrackets | false | CVD-safe rainbow bracket colouring |
dath.rainbowIndents | false | Colour indent guides to match the rainbow bracket palette |
dath.bracketShapeHints | false | Underline hints on bracket pairs |
dath.fontOverride | none | Any installed font name, or none for VS Code default |
dath.fontSizeOverride | 0 | Font size in px (0 = VS Code default) |
dath.lineHeightOverride | 0 | Line height override (0 = VS Code default) |
dath.letterSpacingOverride | 0 | Letter spacing in px (0 = VS Code default) |
dath.activeProfile | "" | Active profile name — managed by Dath |
dath.customPalettes | {} | Custom colour role mappings for Custom 1/2/3 modes |
dath.darkModeProfile | "" | Profile to auto-apply when VS Code switches to a dark theme |
dath.lightModeProfile | "" | Profile to auto-apply when VS Code switches to a light theme |
extension.ts ← entry point, commands, config listener, onboarding
├── cvd.ts ← LMS daltonization engine (zero external dependencies)
├── themeReader.ts ← locates and parses active theme JSON from disk
├── themeEngine.ts ← read → correct → write pipeline (185 tokens)
├── panel.ts ← interactive webview control surface
├── profiles.ts ← named profile save/apply/delete
└── statusBar.ts ← status bar item and toggle
npm install
npm run compile
# Press F5 in VS Code to launch an Extension Development Hostnpm run watch # incremental compilation
npm run lint # ESLint
npm run package # build .vsix for local install or publishingPolyForm Noncommercial 1.0.0 — free to use and modify for non-commercial purposes.