Spectral

A warm, high-contrast colorscheme with an amber-CRT signature, in dark and light variants.

• Spectral Dark — amber phosphor on OLED black
• Spectral Light — warm cream paper, same amber signature

Every target is generated from one palette definition, so the colors match across your editor, your terminal, and everything else.

Ruby with Sorbet type signatures, Markdown headings, and YAML keys in amber:

Dark	Light

Click through for the full-size render. Python samples are in screenshots/.

Where it runs

Application	What ships
Vim / Neovim	colorscheme, lightline theme, Sorbet syntax plugin
VS Code	extension — workbench, TextMate scopes, semantic tokens
Zed	extension — one theme family with both variants
Ghostty	two themes, plus an install script
iTerm2	two presets, plus a profile sync script
Mattermost	two custom themes

Vim and Neovim

With vim-plug:

Plug 'iain/spectral'

With Pathogen, clone into ~/.vim/bundle. Manually, copy colors/ into ~/.vim/colors (Vim) or ~/.config/nvim/colors (Neovim). Then add to your .vimrc or init.vim:

set termguicolors
colorscheme spectral        " picks the variant matching &background

spectral-dark and spectral-light force a variant. Requires Vim 7.4+ or Neovim 0.5+, and a true-color terminal.

Languages — Ruby (including Sorbet), Python, JavaScript, TypeScript, Go, HTML, CSS, Markdown, JSON, YAML, TOML, XML, and Vim script.

Plugins — GitGutter, Signify, fugitive, NERDTree, netrw, ALE, CoC, fzf, CtrlP, Telescope, Startify, and vim-which-key.

Neovim — Treesitter (0.8+), covering both the legacy @text.* captures and the @markup.* names Neovim 0.10 renamed them to; LSP diagnostics, references, code lens, inlay hints and signature help (0.5+); semantic tokens (0.9+); floating windows, WinBar and WinSeparator.

Statusline

A matching lightline.vim theme ships with the colorscheme. Once Spectral is on your runtimepath:

let g:lightline = { 'colorscheme': 'spectral' }

It follows &background once lightline reloads.

Sorbet type signatures

plugin/sorbet.vim loads automatically for Ruby files and dims sig blocks, T:: types and extend T::Sig, so signatures recede behind the code they annotate.

VS Code

vscode/ is a self-contained extension covering the workbench, the integrated terminal's ANSI palette, TextMate scopes, and LSP semantic tokens.

To use it without publishing, link it into your extensions directory and reload:

ln -s "$PWD/vscode" ~/.vscode/extensions/spectral

To build a .vsix:

cd vscode && npx @vscode/vsce package

The mapping departs from the Vim theme in two places, both where the Vim theme is internally inconsistent:

• Punctuation uses fg_alt, following the Treesitter captures rather than the brighter per-language groups (jsonBraces, cssBraces).
• Regular expressions follow the richer rubyRegexp* treatment — cyan body, orange escapes, purple character classes — rather than the flat orange of @string.regex.

Sorbet signatures are not dimmed here; that relies on the syntax regions in plugin/sorbet.vim, which have no TextMate scope to hook.

Zed

zed/ is an extension carrying zed/themes/spectral.json — one theme family with both variants, so Zed's system mode switches between them:

{
  "theme": {
    "mode": "system",
    "light": "Spectral Light",
    "dark": "Spectral Dark"
  }
}

To use it without publishing, either drop the theme file in Zed's themes directory:

ln -s "$PWD/zed/themes/spectral.json" ~/.config/zed/themes/spectral.json

or install the whole directory from the extensions page with Install Dev Extension, which is what publishing to Zed's extension store expects.

Two mappings depart from the Vim theme, both because Zed's captures are coarser than Neovim's:

• Keys keep the amber signature only in JSON, which has a capture of its own (property.json_key). YAML, TOML and CSS share the generic property capture with member access on an object, so amber there would paint every obj.field amber too; they follow body text instead.
• Markdown headings are one color rather than a ladder of six — Zed captures every level as title.

If you would rather have the keys and take the member access with them, Zed's theme_overrides flips that one capture without touching the theme file:

{
  "theme_overrides": {
    "Spectral Dark":  { "syntax": { "property": { "color": "#F9AD26" } } },
    "Spectral Light": { "syntax": { "property": { "color": "#A76C01" } } }
  }
}

Ruby symbols, Python decorators and Markdown list markers carry the signature as they do everywhere else. Regular expressions follow the VS Code reading: Zed injects a regex grammar, so escapes stay orange inside the cyan body. Sorbet signatures are not dimmed, for the same reason they are not in VS Code.

Ghostty

ghostty/spectral-dark and ghostty/spectral-light. Run ghostty/install.sh to symlink them into ${XDG_CONFIG_HOME:-~/.config}/ghostty/themes/, then reference them by name:

theme = dark:spectral-dark,light:spectral-light

Pass --force to replace existing files at the destination.

iTerm2

iterm2/Spectral Dark.itermcolors and iterm2/Spectral Light.itermcolors. Import via Settings → Profiles → Colors → Color Presets → Import.

To wire both variants into one profile so iTerm2's automatic dark/light switching works:

iterm2/sync.py <path-to-com.googlecode.iterm2.plist> [profile-name]

The profile name defaults to Default. The script writes the dark preset to the unsuffixed and (Dark) color keys, and the light preset to the (Light) keys.

Mattermost

mattermost/spectral-dark.json and mattermost/spectral-light.json. Open Settings → Display → Theme → Custom Theme, expand "Copy/Paste Theme Colors", and paste either file. Amber anchors mentions, buttons and the active-channel border; the team rail is the darkest neutral.

The palette

Each variant is defined in OKLCH — lightness 0–1, chroma, and hue in degrees. The accents sit in a roughly equiluminant band, so they feel equally bright across hues, and the neutrals all share one warm hue at low chroma.

Amber is the signature, and it goes on whatever gives a language its texture: the element you see constantly. Ruby symbols came first; the rest were picked one language at a time.

Language	Element
Ruby	symbols
Python	decorators
YAML, JSON, TOML	keys
CSS	property names
JavaScript, TypeScript, Go	object and struct literal keys
Markdown	list markers

HTML, XML and Vim script have no amber yet: nothing in them is both frequent and characteristic enough without swamping the file.

Spectral Dark

Color	OKLCH	Hex	Usage
Amber (signature)	0.80 / 0.16 / 75°	#F9AD26	Symbols, decorators, keys
Red	0.68 / 0.22 / 27°	#FF544C	Keywords, control flow
Orange	0.74 / 0.20 / 50°	#FF8432	Parameters, special characters
Yellow	0.88 / 0.20 / 98°	#F8D700	Strings
Green	0.86 / 0.22 / 135°	#8DEF46	Functions, methods
Cyan	0.80 / 0.13 / 195°	#2AD7D7	Types, built-in functions
Blue	0.72 / 0.18 / 255°	#60A7FF	Links, namespaces
Purple	0.70 / 0.17 / 320°	#CC77DF	Constants, numbers, booleans

Background 0.21 / 0.006 / 85° → #1A1815 · Foreground 0.86 / 0.038 / 85° → #DCD0B5

Spectral Light

Color	OKLCH	Hex	Usage
Amber (signature)	0.58 / 0.124 / 72°	#A76C01	Symbols, decorators, keys
Red	0.50 / 0.200 / 27°	#BB0916	Keywords, control flow
Orange	0.56 / 0.183 / 38°	#C83E01	Parameters, special characters
Yellow	0.64 / 0.131 / 88°	#AD8600	Strings
Green	0.52 / 0.166 / 142°	#1A7F11	Functions, methods
Cyan	0.53 / 0.091 / 205°	#007A85	Types, built-in functions
Blue	0.45 / 0.148 / 255°	#0053A4	Links, namespaces
Purple	0.48 / 0.233 / 302°	#791DC7	Constants, numbers, booleans

Background 0.985 / 0.020 / 85° → #FFFAEE · Foreground 0.26 / 0.030 / 85° → #2B2313

Where a requested chroma falls outside the sRGB gamut, the generator reduces it by bisection, preserving L and H, so each hex is the closest representable color. Some distinctions also depend on the editor: namespaces separate from types only under Treesitter, LSP or semantic tokens, and fall back to cyan in Vim's regex syntax.

Working on the theme

Edit the PALETTES dict in tools/palette.py and run it to regenerate every target in one pass:

python3 tools/palette.py

That writes colors/spectral-*.vim, ghostty/spectral-*, iterm2/*.itermcolors, mattermost/spectral-*.json, vscode/themes/spectral-*.json, vscode/icon.png, zed/themes/spectral.json, screenshots/palette-*.svg, and autoload/lightline/colorscheme/spectral.vim. All of those are generated — do not hand-edit them. After regenerating the iTerm2 presets, run iterm2/sync.py <plist> to push them into your own plist.

Tests

python3 -m unittest discover -s tools

They check the generated output: valid hex everywhere, no TextMate scope claimed by two entries, and a contrast floor. CI runs them alongside a check that the generated files match the palette.

Screenshots

python3 tools/screenshots.py            # every sample, both variants
python3 tools/screenshots.py billing    # only samples matching a stem

Each file in tools/samples/ is rendered through a real headless Vim and written to screenshots/. The colors come from Vim's own :TOhtml rather than from the palette, so a screenshot reports what the colorscheme actually resolved each syntax group to.

This needs vim on PATH, and is not part of the CI drift check: :TOhtml markup shifts between Vim versions, so regenerating on a different Vim produces spurious diffs. Rerun it by hand when the palette changes. The palette-*.svg cards come from tools/palette.py instead, need no Vim, and are drift-checked like every other generated file.

License

MIT