Entire UI is monochrome/black-and-white — no colors, syntax highlighting, or selection indicators

What happened?

After updating Claude Code, the entire UI renders in black and white with no colors at all. Specifically:

• No syntax highlighting in diff previews or code blocks
• No colored cursor on the text input line
• No visible "current selection" highlight in menus (e.g., /config theme picker) — only the > indicator and checkmark are visible, but no color differentiation
• No color differentiation for added/removed lines in diffs

The UI is completely monochrome despite the terminal fully supporting colors (TERM=xterm-256color, COLORTERM=truecolor).

What did you expect?

Colors, syntax highlighting, colored diff markers (red/green), and visible selection highlighting throughout the UI.

Claude Code version

v2.1.52

OS

macOS 15.7.1 (Darwin 24.6.0)

Terminal

Reproduced on multiple terminals: Warp, Ghostty, and default zsh terminal. All exhibit the same monochrome issue.

Additional context

• NO_COLOR is not set
• FORCE_COLOR is not set
• COLORTERM=truecolor
• TERM=xterm-256color
• Issue started after a Claude Code update (not a macOS or terminal update)

Screenshot showing the /config theme picker with completely monochrome rendering:

!monochrome-ui