Copilot CLI colors don't respect terminal theme in Warp

Describe the bug

In Warp terminal (Mac), Copilot CLI changes text colors based on the system light/dark mode setting, regardless of the terminal color theme. This means if you have light mode set at the OS level, but use a dark theme in Warp the text colors assume a light background and are unreadable on the dark background. There does not seem to be a way to force dark mode through the /theme settings.

Affected version

GitHub Copilot CLI 1.0.84-6

Steps to reproduce the behavior

1. Set the Mac OS-level appearance to light mode.
2. Choose a dark theme in the Warp terminal settings.
3. Start Copilot.

Results:
Copilot launches in the correct (dark) theme, then switches to light mode colors. The text is difficult (in some cases impossible) to read.

Expected behavior

Copilot CLI should use a text theme appropriate to the terminal color theme, not the OS color theme.
If the terminal is set to a dark theme, use a dark text color theme regardless of the OS setting.

Additional context

Mac OS 15.7.9
Warp v0.2026.09.09.08.26.stable_02
Warp theme "Fancy Dracula"
GitHub Copilot CLI 1.0.84-6

Workarounds:

• Changing the system-level appearance to dark causes Copilot to switch to the proper colors
• Changing Warp to use a light theme makes the text readable again
• Using the default Mac terminal seems to work as expected.
• Reverting to Copilot v1.0.84-5 works as expected.

まず、macOS の外観をライトに設定し、Warp で Fancy Dracula テーマを使用した状態で、Copilot CLI 1.0.84-6 の問題を再現します。Copilot 1.0.84-5 およびデフォルトの Mac ターミナルでの動作と比較し、その後 /theme と terminal-color の処理を追跡します。OS の外観設定に関係なく、Warp のダークテーマが読みやすい状態を保てれば完了です。