fix(theme): improve theme color contrast for macOS Terminal.app

[clocky]

Summary

Updates both light and dark theme colors to ensure a minimum 4.5:1 contrast ratio in xterm-256 environments, specifically targeting improved visibility and accessibility for macOS Terminal.app.

Details

• Adjusted colors to meet 4.5:1 contrast standards against the default black background.
• Adjusted colors to meet 4.5:1 contrast standards against the default white/light-gray background.
• Scope: This PR only targets the default and definitions; no other themes (e.g., Ayu, GitHub, Solarized) are affected.
• Replaces fix(theme): update default theme colors for improved contrast #21169 which was closed by automation.

Related Issues

Fixes #21170

[gemini-code-assist]

Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request enhances the accessibility and readability of the CLI's default themes by adjusting color palettes to meet WCAG contrast ratio standards. The updates specifically benefit users of macOS Terminal.app, providing a more comfortable visual experience without impacting other theme configurations.

Highlights

• Improved Color Contrast: Updated both light and dark theme colors to ensure a minimum 4.5:1 contrast ratio in xterm-256 environments.
• Targeted Accessibility: Specifically improved visibility and accessibility for macOS Terminal.app users.
• Scope Limitation: Changes are limited to the default lightTheme and darkTheme definitions; other themes are unaffected.

Changelog

• packages/cli/src/ui/themes/theme.ts
  • Modified color definitions for the lightTheme to achieve a 4.5:1 contrast ratio against a light background.
  • Modified color definitions for the darkTheme to achieve a 4.5:1 contrast ratio against a dark background.
  • Replaced interpolateColor calls with direct hex color values for several theme properties in both light and dark themes.

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[gemini-code-assist]

Code Review

This pull request updates the color palettes for the light and dark themes to improve contrast and accessibility, particularly for macOS Terminal.app. The changes involve replacing dynamically generated colors with hardcoded values that meet a 4.5:1 contrast ratio. While this is a positive step for accessibility, I've identified a few instances where different semantic color properties have been assigned the same hex value in both themes. This reduces visual distinction and should be addressed to improve UI clarity. My review includes specific comments on these duplicated color assignments.

[github-actions]

Size Change: -554 B (0%)

Total Size: 26 MB

ℹ️ View Unchanged

Filename	Size	Change
./bundle/gemini.js	25.5 MB	-554 B (0%)
./bundle/node_modules/@google/gemini-cli-devtools/dist/client/main.js	221 kB	0 B
./bundle/node_modules/@google/gemini-cli-devtools/dist/src/_client-assets.js	227 kB	0 B
./bundle/node_modules/@google/gemini-cli-devtools/dist/src/index.js	11.5 kB	0 B
./bundle/node_modules/@google/gemini-cli-devtools/dist/src/types.js	132 B	0 B
./bundle/sandbox-macos-permissive-open.sb	890 B	0 B
./bundle/sandbox-macos-permissive-proxied.sb	1.31 kB	0 B
./bundle/sandbox-macos-restrictive-open.sb	3.36 kB	0 B
./bundle/sandbox-macos-restrictive-proxied.sb	3.56 kB	0 B
./bundle/sandbox-macos-strict-open.sb	4.82 kB	0 B
./bundle/sandbox-macos-strict-proxied.sb	5.02 kB	0 B

_{compressed-size-action}

[jacob314]

[clocky]

The PR correctly addresses the contrast issues for xterm-256 terminals (like macOS Terminal.app) by adopting a high-contrast palette based on the xterm-256 standard.

I have updated the snapshots and fixed the two test failures in and that were caused by the color changes and the new default background.

Observations:

• Visual Shift: This change significantly alters the default 'Default' and 'Default Light' themes for all users, moving from a soft palette to a very high-contrast ANSI-based one.
• CI Fixes: CI was failing due to 41 mismatched snapshots and 2 logic-related test failures. These are now resolved in the latest commit.
• Derived Colors: Derived semantic colors (like ) are now hardcoded hex values instead of using . This is a reasonable trade-off to ensure correct color mapping on 256-color terminals.

The code follows the repository's strict development rules and uses established React/Ink patterns.