fix(theme/persist): apply custom colors only when theme == Custom; clear [tui.theme].colors/label when switching to built-in themes so startup doesn’t force Custom palette

codex-rs/core/src/config.rs

@@ -386,6 +386,14 @@ pub fn set_tui_theme_name(codex_home: &Path, theme: ThemeName) -> anyhow::Result
 
     // Write `[tui.theme].name = "…"`
     doc["tui"]["theme"]["name"] = toml_edit::value(theme_str);
+    // When switching away from the Custom theme, clear any lingering custom
+    // overrides so built-in themes render true to spec on next startup.
+    if theme != ThemeName::Custom {
+        if let Some(tbl) = doc["tui"]["theme"].as_table_mut() {
+            tbl.remove("label");
+            tbl.remove("colors");
+        }
+    }
 
     // ensure codex_home exists
     std::fs::create_dir_all(codex_home)?;

codex-rs/tui/src/theme.rs

@@ -57,7 +57,12 @@ impl Default for Theme {
 /// Initialize the global theme from configuration
 pub fn init_theme(config: &ThemeConfig) {
     let mut theme = get_predefined_theme(config.name);
-    apply_custom_colors(&mut theme, &config.colors);
+    // Important: Only apply color overrides for the Custom theme.
+    // Built-in themes should render exactly as defined so that switching away
+    // from Custom does not keep stale custom overrides from config.
+    if matches!(config.name, ThemeName::Custom) {
+        apply_custom_colors(&mut theme, &config.colors);
+    }
 
     // On some terminals (notably macOS Terminal.app with certain profiles),
     // truecolor escape sequences may render incorrectly. Detect such cases