Theme reference
Theme Format
nameis required, must be unique, and must not contain/.varsis optional. Define reusable colors here, then reference them incolorsorworkingIndicator.colorsmust define all 51 required tokens.scrollbarThumbis optional and falls back toselectedBgwhen omitted.searchMatchBgandsearchMatchTextremain accepted for older theme files but are unused.workingIndicatoris optional and may override any subset of the six tones in the outward half of the ordinary∀ramp; Atomic derives omitted tones from selected background, accent, and text roles, then mirrors the palette back afterpeak. Explicit numeric values from 0 through 255 remain exact terminal palette indices. When a numeric index from 0 through 15 seeds an omitted tone, Atomic mixes from its built-in approximation of the common ANSI RGB value; the terminal still controls the actual appearance of the explicit index. Both explicit and derived tones update on theme hot reload.
$schema field enables editor auto-completion and validation.
Color Tokens
Every theme must define all 51 required color tokens. The optional tokens preserve compatibility with themes written before they existed:scrollbarThumb and unused searchMatchBg fall back to selectedBg, and unused searchMatchText falls back to text.
Core UI (11 colors)
Backgrounds & Content (11 required, 3 optional)
Markdown (10 colors)
Tool Diffs (3 colors)
Syntax Highlighting (9 colors)
Thinking Level Borders (6 colors)
Editor border colors indicating thinking level (visual hierarchy from subtle to prominent):Bash Mode (1 color)
HTML Export (optional)
Theexport section controls colors for /export HTML output. If omitted, colors are derived from userMessageBg.
Color Values
Four formats are supported:256-Color Palette
0-15: Basic ANSI colors (terminal-dependent)16-231: 6×6×6 RGB cube (16 + 36×R + 6×G + Bwhere R,G,B are 0-5)232-255: Grayscale ramp