[FEATURE] distinguishing user prompts from assistant responses in long threads

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

In long threads, scrolling back to find a specific earlier question requires reading line by line. There's no visual anchor to quickly locate user turns vs assistant turns.

Proposed Solution

Distinct color for user input lines — even a subtle background or foreground difference on the "You:" block would help scanning significantly. The custom theme system exposes briefLabelYou and briefLabelClaude tokens but these only affect the small label, not the full message block.

Keyboard navigation between user turns — a keybinding (e.g. Alt+Up / Alt+Down) to jump directly between user messages in the conversation history, similar to how some terminals let you jump between shell prompts.

Visual separator — a horizontal rule or indentation difference between user and assistant blocks would help even without color changes, and would work across all themes including ANSI/accessible ones.

Configurable color support for user vs assistant message blocks — extend the custom theme system in settings.json to allow users to set distinct foreground/background colors for the entire user message block and assistant message block, not just the label. For example:

{
"theme": {
"userMessageColor": "#a8d8a8",
"assistantMessageColor": "#d8d8d8"
}
}
This would make long threads scannable at a glance without relying on labels alone.

Alternative Solutions

_No response_

Priority

Medium - Would be very helpful

Feature Category

Configuration and settings

Use Case Example

_No response_

Additional Context

_No response_