Light (ANSI only) theme uses ANSI white for syntax, invisible on light terminals

Description

When using Light mode (ANSI colors only) (option 6 in /theme), code snippets and diffs render certain text elements using ANSI white (palette 7 / escape code 37). On light terminal themes, ANSI white is typically a very light color (close to the background), making this text invisible.

Affected elements

• Code punctuation: (), {}, ; — rendered in ANSI white, invisible on light backgrounds
• Deleted diff lines — struck-through text uses ANSI white, completely invisible
• Line numbers on certain lines

Steps to reproduce

1. Use any light terminal theme where palette 7 (ANSI white) is a light/warm color (this is standard — Solarized Light, Catppuccin Latte, etc. all do this)
2. Run claude and select /theme → Light mode (ANSI colors only)
3. Make any code change to trigger a diff view
4. Observe that punctuation and deleted lines are invisible

Why this happens

In the 16-color ANSI palette, slot 7 ("white") has different semantics depending on background:

• Dark themes: ANSI white = light foreground text (readable on dark bg)
• Light themes: ANSI white = a light/cream color, essentially a background-adjacent tone

Most terminal programs avoid using ANSI white as foreground text for this reason — they use the terminal's foreground setting instead. The light-ansi theme appears to map syntax elements to ANSI white, which breaks on any light terminal where palette 7 is light.

Expected behavior

The light-ansi theme should avoid using ANSI white (palette 7) for text elements that need to be readable. Use ANSI bright black (palette 8) or the terminal's default foreground instead.

Environment

• Claude Code: 2.1.86
• Terminal: Ghostty (but this affects any terminal with a standard light ANSI palette)
• OS: macOS

Screenshots will be added in a follow-up comment — gh CLI doesn't support image attachments.