Codex customization guide

How to customize Codex without losing the plot.

Start with the official appearance controls. Add an external background only when the extra visual layer is worth a separate local trust boundary.

Use native Codex appearance settings first

Native Codex themes are the lowest-risk option for changing the base theme, accent, foreground, background, and fonts. They do not provide an image background, but they are easy to share and restore.

Best for: color and typography changes with no external theme engine.

Use a custom Codex background for atmosphere

A background theme adds an image layer behind the native interface. Good results depend less on the image itself than on crop, panel opacity, dimming, and keeping detailed subjects away from the reading column.

Open the local theme studio

Keep design and installation separate

CodexSkin exports a recipe that you can inspect. The separate Codex Dream Skin project handles local installation and restore through loopback-only CDP. A theme archive should not hide scripts or provider settings.

Never run a theme installer that silently changes API keys, model providers, or remote Base URLs.

Check the states where real work happens

Home: headline and suggestions stay readable.
Task: long conversations and controls keep clear contrast.
Diff: additions and removals remain unmistakable.
Navigation: active and hover states are visible.
Restore: you know how to return to the official appearance.