Thinking/reasoning text is unreadable on dark backgrounds (hardcoded dim color)

[ayackel]

Describe the bug

The "Thinking…" reasoning text displayed during model inference is nearly invisible on dark terminal backgrounds. The text appears to use a hardcoded dark gray foreground that has insufficient contrast against dark backgrounds.

This started with a recent update (noticed on 1.0.64).

Environment

• OS: Windows 11 + WSL2
• Terminal: Windows Terminal (dark color scheme)
• Multiplexer: tmux
• Copilot CLI version: 1.0.64
• Model: Claude Opus 4.6 (extended thinking enabled)

Steps to reproduce

1. Use a dark terminal color scheme (default Windows Terminal dark, or similar)
2. Run copilot in tmux
3. Ask a question that triggers extended thinking/reasoning
4. Observe the "Thinking…" block text is nearly invisible

Expected behavior

Thinking/reasoning text should have sufficient contrast on both dark and light backgrounds. Ideally it would:

• Use a semantic ANSI color (e.g., brightBlack / color 8) rather than a hardcoded RGB
• Or respect the terminal's dim attribute rendering
• Or be configurable via a theme/config setting

Workaround

Bumping brightBlack in the Windows Terminal color scheme to #808080 or lighter partially helps, but this affects all dim text globally.

Related issues

• Hardcoded colors in 1.0.61 break the light themed CLI #3750 — Hardcoded colors break light themes (same root cause, opposite direction)
• Feature Request: Fine-grained per-element theming (border colors, chevron, prompt vs response foreground) #2123 — Feature request for per-element theming (would solve this)
• Add custom theme support #1504 — Custom theme support request