How to install themes in the Codex app
The OpenAI Codex desktop app ships with appearance settings — built-in themes, custom colors, and theme importing. Here are the three ways to change how it looks, fastest first.
1. The install-prompt route (our favorite)
Every theme on CodexSkins has a Copy install prompt button. The prompt is a short instruction that tells Codex to create a custom theme with the exact hex values shown on the page, restrict itself to appearance settings, and report back everything it changed. Paste it into the Codex input like any other task. Done — usually in one turn, no files touched, fully reversible.
Why this beats manual setup: you never hunt through menus, it works the same on macOS and Windows, and the agent's reply doubles as your undo list.
2. Appearance settings, by hand
Open Settings → Appearance in the Codex app. You can switch between built-in presets, flip dark/light, adjust accent colors, and — where available — create a custom theme. Copy the hex values from any CodexSkins theme page (each page lists all 13 tokens) into the matching slots.
3. Importing a shared theme string
Themes travel around X and team chats as long codex-theme-v1:…strings. The appearance settings include an import option that accepts them. Two tips: never import a string you haven't previewed — paste it into our preview tool first to see what you're getting — and if the importer rejects a string, fall back to route 1, which sidesteps import validation entirely.
Troubleshooting
? My imported theme looks wrong in light mode.
Most shared themes define one variant. If a theme only ships dark colors, keep the app in dark appearance, or grab the light sibling from our gallery (every CodexSkins palette lists its variant on the card).
? The import was rejected.
Import validation is strict about structure — a hand-edited string with a missing field can fail silently. Easiest fix: skip the string entirely and use the install prompt, which applies colors through settings instead of the importer.
? How do I go back to the default look?
Appearance settings always keep the built-in presets — select one and you're back to stock. Our install prompts also ask the agent to list every change it made, so you can undo selectively.
Ready to pick? Start with trending themes or the full Codex gallery.