Running OpenCode inside Ghostty on Omarchy produced a near-unreadable light-gray-on-light-gray interface. The logo, prompt text, and status bar were all washed out. Switching Omarchy themes didn't help — the TUI stayed stuck in a light palette regardless of whether the system was using Catppuccin (dark), Tokyo Night, or anything else.
First I checked what OpenCode thought the system theme was. Its tui.json was set to "theme": "system", which means it tries to auto-detect light vs dark mode.