Build a Codex theme you can inspect before you copy
Adjust the palette, semantic diff colors, fonts, and window behavior while watching a live Codex preview. The builder validates the CodexThemes contract locally and writes the result to your clipboard only when you choose Copy.
Safe & local — no account, upload, or server storage.
Started from Lavender Soft. Stored only in this browser.
Theme editor
Advanced settings
Chat preview · Light
Live Codex preview
I rebuilt the theme browser around a denser palette list and a more faithful Codex workspace preview.
The selected theme now updates navigation, conversation surfaces, diff colors, active states, and the composer in one view.
Edited 7 files
+129 −42
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Understand the format before applying a theme
Official Codex App documentation confirms customizable colors, fonts, and theme sharing, but does not publish a stable import string contract. Use visible Codex controls and stop if your installed version does not offer the workflow you expect.