All platforms · 7 min · Upstream checked July 17, 2026

Customize Codex theme colors without losing readability

Build an accent system for focus, secondary information, and highlights instead of choosing three decorative swatches.

Platform behavior can change. Compare this guide with the original repository at commit 26c6c410e0e0.
01Extract three local palette options
02Assign colors by role
03Test each content surface
04Export a versioned recipe

Give each color a job

Accent should mark the primary action and focus state. Secondary can support links or informative states. Highlight should remain available for selection, emphasis, or a contrasting signal. When all three colors compete at the same intensity, the interface loses hierarchy even if each swatch looks attractive alone.

Evaluate surfaces, not a single average

The Builder reports sampled contrast separately for sidebar, cards, and composer. Raise overlay or surface opacity where text intersects a bright crop. Then switch through Home, Task, Diff, Terminal, and Settings because a palette can work on large headings while failing on compact metadata or code lines.

Keep the recipe portable

Download recipe v2 after naming the theme and finalizing surface values. The JSON stores settings but no image bytes. Share links follow the same rule. This separation makes review safer and lets another person supply their own local wallpaper without receiving yours.

Automated contrast is a sampled estimate. Verify real text sizes, focus rings, errors, additions, removals, and disabled states visually.

Completion checklist

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