Quick answer
Learn where Codex Appearance settings live, what each native theme control changes, how sharing works, and when a custom visual theme uses a separate unofficial layer.
Open Codex Appearance settings
Open Settings from the Codex app menu, then choose Appearance. The desktop shortcut is Cmd+, on macOS or Ctrl+, on Windows. Start here whenever you want the most update-resistant way to change how Codex looks.
The current official settings documentation describes controls for a base theme, accent color, background color, foreground color, UI font, code font, and sharing a custom theme.
Choose a base theme first
The base theme establishes the overall light or dark foundation. Choose the foundation that matches your room lighting and normal working hours before fine-tuning individual colors.
A good base keeps the task surface, sidebar, menus, composer, code, and diff states readable without relying on decorative artwork.
Adjust accent, background, and foreground
Accent color controls emphasis such as active controls and selected states. Background and foreground colors define the primary surface and text relationship. Treat the three values as one contrast system instead of choosing each color in isolation.
- Check normal text, muted labels, links, and keyboard focus states.
- Open a real task with code and a diff instead of judging only an empty home screen.
- Test the same settings in a narrow window and in your usual light or dark environment.
Set UI and code fonts separately
Codex Appearance settings let you change the UI font and code font independently. Use the UI font for comfortable navigation and reading, then choose a code font with clear punctuation, brackets, and similar-looking characters.
After changing either font, inspect dense tool output and long file paths. A font that looks attractive in a short label can become tiring in an extended coding session.
Share a custom native theme
The official desktop settings support sharing your custom theme with other people. Before sharing, verify the theme in the current stable app and describe whether it was designed for a light or dark foundation.
Keep a known-good built-in appearance available as the return path. Recipients should be able to compare the shared look with a stock baseline without changing unrelated Codex settings.
Know what is outside native Appearance
A native Appearance theme changes the controls documented by Codex. Artwork-heavy backgrounds, route-aware overlays, and decorative layout treatments are a different category and should not be described as built-in Codex features.
Get Codex Theme labels those advanced visual packs as unofficial. They use a separate, reversible local compatibility layer, remain outside the signed application package, and need their own activation and restore instructions.
Do not confuse desktop and CLI themes
Codex Desktop Appearance and the Codex CLI theme picker are separate systems. In the CLI, run /theme to preview and save a terminal theme. Custom CLI themes use .tmTheme files placed in $CODEX_HOME/themes.
A desktop theme should not claim to configure terminal syntax highlighting, and a CLI .tmTheme file should not be presented as a full desktop Appearance theme.
Compatibility note: Native Codex appearance controls and advanced visual image layers are different. Get Codex Theme labels the delivery path and never treats an experimental visual layer as an official Appearance feature.
Primary sources