Slatis Nyx

Six dark variants, three of them built for colour vision deficiency

Mantained by @utreras

           

A gift from Slatis engineers to other engineers who work while everyone sleeps.

Nyx was the goddess of night, and in every telling, night is not the absence of something. It is its own thing, first-born, with its own weather. The room gets quiet, the meetings stop, and what is left is you and the problem(s).

Why?

Around 1 in 12 men & 1 in 200 women have some form of colour vision deficiency, and syntax highlighting asks them to pull meaning out of hue for eight hours a day. Most themes hand them two roles painted the same colour and ship it.

Slatis Nyx generates six variants from one source palette. Three target a specific deficiency, one drops colour out of the interface completely, and the build refuses to finish when two syntax roles could read as the same colour.

Features

• Functions render purple #c9a3f0, so the interface accent and the code never share a hue.
• Borders: Two bands with one rule: #2c2e2d for surfaces that sit inside the layout, #383a39 for surfaces that float over content.
• Semantic highlighting, on. 39 rules keyed off the language server, so readonly locals, defaultLibrary symbols and declarations each read differently from a plain identifier.
• Punctuation recedes to #8e8f8f and lets keywords own the accent.
• Every surface is covered. Terminal ANSI, diff, merge, git decorations, bracket pairs, inlay hints, sticky scroll, the command centre, the source control graph, symbol icons, and the chat view.

Variants

Built for colour vision deficiency

Syntax highlighting asks them to pull meaning out of hue for eight hours a day, and most themes hand them two roles painted the same colour.

Three variants target a specific deficiency, and a fourth removes the question entirely.

Deuteranopia and Tritanopia keep the interface exactly as the default theme paints it. What moves is the syntax palette, the git and diff signals, the 16 terminal ANSI colours and the source control graph lanes, which is everywhere colour carries meaning rather than identity.

Every palette was measured

Every variant is generated from one source theme by scripts/build-variant.js, and the build refuses to finish when two of the ten syntax roles could read as the same colour.

A pair passes when at least one of three channels carries the difference:

• a luminance gap of 0.03
• a hue gap of 70 degrees
• one of them sitting near neutral, where chroma does the work

Hue remapping on its own leaves pairs that match in both hue and value. Measuring all 45 pairs in each variant surfaced entity and tag sitting 0.001 apart in luminance and 61 degrees apart in hue, which lands as a single colour for a deuteranope. The palettes moved until the check passed.

Colour works alongside other channels

Read-only symbols render bold in every accessibility variant, so a constant stays identifiable with hue stripped out completely. Deprecated symbols are struck through in all six.

Mono takes the idea furthest. The git gutter separates added, modified and deleted by lightness, and 41 keys covering errors, warnings, merge conflicts, offline state and breakpoints hold their colour, so a failure still announces itself in a greyscale interface.

What a theme cannot reach

These live in settings, beyond the reach of any colour file:

{
  // Force a minimum contrast ratio in the terminal, overriding program colours
  "terminal.integrated.minimumContrastRatio": 4.5,

  // Heavier glyphs help low vision more than brighter ones
  "editor.fontWeight": "500",
  "workbench.fontAliasing": "antialiased",

  // A wider, steady caret is easier to track
  "editor.cursorWidth": 3,
  "editor.cursorBlinking": "solid",

  // Audio cues that run independently of anything visual
  "accessibility.signals.lineHasError": { "sound": "on" },
  "accessibility.signals.lineHasWarning": { "sound": "on" },

  // Structure that survives without colour
  "editor.guides.bracketPairs": "active",
  "editor.renderWhitespace": "boundary"
}

Colour contract

Badges split by intent. Counters that report a change, like git and extensions, come through activityBarBadge in blue. Anything asking for attention comes through activityErrorBadge in red or activityWarningBadge in yellow.

The command centre, sticky scroll and the active activity-bar item use alpha compositing, so layers read as stacked glass. Alpha composites against the workbench surface underneath. VS Code has no window-level transparency, so the desktop stays hidden.

Install

Search Slatis Nyx in the Extensions view and install it. Then press Cmd+K Cmd+T (Ctrl+K Ctrl+T on Windows and Linux) and pick a variant.

From a terminal:

code --install-extension utreras.slatis-nyx       # Visual Studio Code
cursor --install-extension utreras.slatis-nyx     # Cursor
windsurf --install-extension utreras.slatis-nyx   # Windsurf
codium --install-extension utreras.slatis-nyx     # VSCodium

Published to both registries, so every VS Code-compatible editor can reach it:

Editors that ship their own registry mirror Open VSX, so one publish there covers all of them. Grabbing the .vsix from either page and running Extensions: Install from VSIX works everywhere as a fallback.

License

MIT