Light-mode UX: past user messages are hard to distinguish from assistant output when scrolling back

Problem

When using Claude Code in a light-mode terminal, scrolling back through a long session to find what I sent (versus what Claude responded) is difficult. Past user messages are visually almost identical to surrounding assistant output — both are plain text on the same background. The only marker is the > prefix, which is easy to miss when skimming.

The active input box has nice highlighting (light blue background on the line being typed), but that styling disappears the moment a message is submitted, so it doesn't help with scroll-back navigation.

Use case

Long sessions where I want to:

• Re-read what I asked Claude two messages ago
• Find the exact phrasing of a past prompt to copy/edit
• Remind myself of the thread of a multi-turn conversation

Right now this means slowly scanning for > characters, which is tedious in a terminal full of mixed output.

Workarounds I've tried

• iTerm2 triggers with regex ^> .* and a Highlight Line action: unreliable inside a TUI because Claude Code redraws regions and can overwrite the highlight.
• iTerm ⌘F search for > : works, but requires a manual search every time.
• Switching terminals (Ghostty, WezTerm, Kitty): doesn't help — the limitation isn't terminal-side, it's that Claude Code's TUI renders user and assistant lines with the same styling.

Proposed solutions (either would work)

1. Theme option for past user messages: a setting (e.g. in settings.json) that gives committed user messages a subtle background tint, similar to how Cursor, Warp, and the ChatGPT desktop app distinguish user vs assistant turns. Light-mode and dark-mode variants both helpful.
2. Emit a custom ANSI/OSC marker on user message boundaries: lets terminals (iTerm, WezTerm) hook into a clean, stable signal to style messages themselves.

Option 1 is more universal since not every user has a triggers-capable terminal.

Environment

• Claude Code v2.1.128
• iTerm2, light mode, macOS
• Affects any light-mode terminal user