Feature Request: User-configurable color themes and conversation input highlighting

Summary

Add user-configurable color themes to the Claude Code CLI interface, with specific focus on highlighting user input lines to improve conversation navigation and readability.

Problem Statement

When working through long technical conversations with multi-paragraph responses, it becomes difficult to quickly locate specific questions or inputs when scrolling through conversation history. All text (user input and AI responses) appears in the same visual style, making it challenging to:

• Quickly scan and find where I asked specific questions
• Identify conversation boundaries when reviewing work
• Navigate back to context from earlier in the session
• Distinguish between my input and Claude's responses at a glance

This is particularly problematic for:

• Infrastructure/DevOps work with lengthy explanations and code blocks
• Debugging sessions with multiple rounds of questions
• Planning sessions where reviewing earlier decisions is important
• Any workflow involving frequent scrolling through conversation history

Proposed Solution

1. User-Configurable Color Themes

Add a \theme\ section to \~/.claude/settings.json\ or \~/.claude/settings.local.json\:

\\\json
{
"theme": {
"userInputColor": "#ff9500",
"userInputBackground": null,
"promptSymbol": "❯❯",
"promptColor": "#ff9500",
"aiResponseColor": "#ffffff",
"highlightUserMessages": true,
"conversationSeparator": {
"enabled": true,
"color": "#444444",
"style": "line"
}
}
}
\\\

2. Specific Highlighting Options

User Input Line Highlighting (Highest Priority)

• Color the line where user types their question/command
• Apply color to prompt symbol (e.g., \❯❯\, \>\, \$\)
• Optional: Background color for user input lines
• Should be clearly visible when scrolling

Example Visual:
\\\`
[Normal conversation text in default color]
[Normal conversation text in default color]

❯❯ How do I configure secrets? ← THIS LINE IN ORANGE/YELLOW

[Claude's response in default color]
[Claude's response in default color]

❯❯ What about monitoring? ← THIS LINE IN ORANGE/YELLOW

[Claude's response in default color]
\\\`

3. Additional Theme Options

Message Background Colors:

• Optional alternating backgrounds for user vs AI messages
• Subtle shading to distinguish conversation turns

Conversation Separators:

• Visual divider lines between conversation turns
• Configurable color and style (line, dots, custom character)

Syntax Highlighting:

• Allow customization of code block colors
• Tool result output styling

Use Cases

Use Case 1: Infrastructure Engineer

Working on complex Terraform configurations with multiple rounds of questions about module patterns, security reviews, and deployment workflows. Need to quickly reference earlier questions about specific architectural decisions.

Use Case 2: Debugging Session

Long back-and-forth debugging conversation with logs, error messages, and diagnostic commands. Need to find the exact question that led to a breakthrough solution.

Use Case 3: Learning/Research

Asking multiple questions about a codebase or technology. Want to review the questions I asked to ensure I covered all topics.

Benefits

1. Improved UX: Easier navigation through long conversations
2. Time Savings: Faster to locate specific questions without reading entire transcript
3. Accessibility: Visual markers help users with different cognitive processing styles
4. Consistency: Matches user expectations from other CLI tools (colored prompts, themes)
5. Customization: Users can adapt interface to their preferences and terminal color schemes

Alternatives Considered

Workaround 1: Shell Prompt Customization

• ✅ Works in regular terminal
• ❌ Doesn't affect Claude Code interactive interface
• ❌ Only colors the prompt, not the input line in conversation view

Workaround 2: Manual Visual Markers

• ✅ Can add \>>>\ or \===\ markers manually
• ❌ Requires extra typing
• ❌ Inconsistent across sessions
• ❌ Doesn't help when reviewing others' sessions

Workaround 3: Terminal Color Schemes

• ✅ Can adjust terminal colors globally
• ❌ Affects all terminal output, not just Claude input
• ❌ No fine-grained control over conversation elements

Implementation Notes

Minimal Viable Feature

At minimum, just adding user input line color would solve 80% of the use case:

\\\json
{
"theme": {
"userInputColor": "#ff9500"
}
}
\\\

This single setting would make user questions highly visible when scrolling.

Progressive Enhancement

• Phase 1: User input color only
• Phase 2: Prompt symbol customization
• Phase 3: Full theme system (backgrounds, separators, etc.)
• Phase 4: Pre-built theme presets (dark, light, high-contrast)

Backward Compatibility

• If no \theme\ config exists, use current default behavior
• Invalid color values fall back to defaults
• Per-setting fallbacks ensure graceful degradation

Example Configuration Scenarios

Scenario 1: Minimal (Orange Input)

\\\json
{
"theme": {
"userInputColor": "#ff9500"
}
}
\\\

Scenario 2: High Contrast

\\\json
{
"theme": {
"userInputColor": "#ffff00",
"promptSymbol": ">>>",
"promptColor": "#ffff00",
"highlightUserMessages": true,
"conversationSeparator": {
"enabled": true,
"color": "#666666",
"style": "line"
}
}
}
\\\

Scenario 3: Subtle (Gray Separators)

\\\json
{
"theme": {
"userInputColor": "#88ccff",
"conversationSeparator": {
"enabled": true,
"color": "#333333",
"style": "dots"
}
}
}
\\\

Related Features

This could integrate well with:

• Session export/sharing (preserve theme in exports)
• Multi-agent conversations (different colors per agent)
• Conversation history search (highlight matches in user input)
• Context window indicators (color-code based on token usage)

Community Interest

This feature would benefit:

• Power users with long sessions
• Teams sharing conversation transcripts
• Users with accessibility needs
• Anyone working in complex technical domains

References

Similar features in other CLI tools:

• Zsh/Bash: Custom prompt colors via \PS1\/\PROMPT\
• Git: Color output configuration via \git config color.*\
• Vim: Full theme customization via \colorscheme\
• tmux: Status line and pane border colors
• VSCode: Comprehensive theme system

Additional Context

• Platform: macOS
• Terminal: iTerm2/Terminal.app
• Shell: zsh

Thank you for considering this feature request! Happy to provide additional details or mockups if helpful.