Codex Themes: Browse, Preview & Apply Custom Skins for the Codex CLI & App

The Codex CLI is a Ratatui-based terminal interface, and its color scheme lives in one place: the tui.theme key under the [tui] block of ~/.codex/config.toml, written as a kebab-case name (for example theme = "catppuccin-mocha"). The fastest way to set it is typing /theme in any session, which opens a live-preview picker that updates code samples as you move through options and writes your choice back to that file.

For a theme that is not in the built-in list, drop a .tmTheme file, a TextMate-format theme file, into ~/.codex/themes/. These come from sources like the Catppuccin project or general TextMate theme repositories, and Codex will pick them up as additional entries in the /theme picker. Codex also supports profile-scoped themes: adding [profiles.<name>.tui] theme = "..." overrides the root setting only when that profile is active, which is useful if you run Codex against more than one project with different terminal setups.

# ~/.codex/config.toml
[tui]
theme = "catppuccin-mocha"
animations = true
alternate_screen = "auto"

# Optional: override just for one profile
[profiles.work.tui]
theme = "solarized-dark"

Data as of 2026-07-16. Config keys and behavior are per the official config reference at developers.openai.com/codex; the CLI theme system does not read Codex Dream Skin or MOLTamp installs, since both operate outside config.toml.

The desktop app keeps its theme controls separate from the CLI. Open Settings with Cmd+, then go to Appearance to reach a base theme selector (Light, Dark, or System, which follows your OS), plus individual controls for accent color, background color, foreground or ink color, window opacity, UI font, code font, and semantic diff colors (diffAdded, diffRemoved, skill). The app's built-in library reportedly includes Catppuccin, Monokai, and Solarized variants alongside a handful of partner themes matching third-party products.

Every combination of those settings can be exported as a single codex-theme-v1 string from the same Appearance panel, and importing one from a teammate applies every setting at once instead of rebuilding it field by field. That format is covered in the next section.

codex-theme-v1 is the JSON format the desktop app uses to package a full theme into one portable string: a codeThemeId reference, accent/ink/surface hex colors, a contrast level, UI and code font names, a window-opacity flag, semantic diff colors, and a dark-or-light variant flag. The whole thing ships with a codex-theme-v1: prefix, which the app strips before parsing the rest as standard JSON.

codex-theme-v1:{"codeThemeId":"one","variant":"dark","theme":{"accent":"#cba6f7","ink":"#cdd6f4","surface":"#1e1e2e"}}

Paste a string like that into Settings → Appearance → Import and it applies immediately. Export works the same way in reverse, which makes three sharing patterns practical for teams standardizing on the same Codex themes: committing an exported string to a team dotfiles repo, embedding it as a comment in a project's AGENTS.md so new contributors can paste it in on day one, or packaging it inside a Codex plugin's plugin.json under appConfig so the theme applies automatically when someone installs that plugin.

The official Codex themes, CLI config.toml and the app's Appearance panel, are part of Codex itself, so there is nothing extra to trust. Codex Dream Skin is the one worth reading before you run it, since it is a third-party script rather than an OpenAI feature.

Its own documentation is specific about what it does and does not touch: it applies themes through local Chrome DevTools Protocol (CDP) injection bound to 127.0.0.1 only, it does not modify the Codex .app bundle, app.asar, or WindowsApps package, and it does not automatically rewrite your API key or base URL configuration. That is a narrower footprint than a lot of "reskin your app" tools attempt. It is still a local script with CDP access to a running Codex session though, so the usual local-automation habits apply: read the installer before running it, and avoid running unfamiliar programs on the same machine while it is active, which the project's own README also calls out.

MOLTamp works at a different layer entirely. It wraps the terminal Codex runs inside rather than touching Codex's own process, so from Codex's point of view nothing about the session changes; the visual layer sits outside it in the surrounding shell.