[BUG] The "default" color for session name is unreadable on light theme

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

First session renaming (the /rename command) doesn't change its color to cyan (as it's used to in prior Claude Code releases) but leaves it default.

Apparently this was the result of the below fix in the Claude Code v2.1.246 release:

Fixed /rename replacing the theme's prompt border color (including a custom theme's promptBorder) with the default cyan; the border now keeps your theme's color unless you pick one with /color

At the end session name is barely readable on the light theme.

What Should Happen?

The contrast ratio of session name for light theme should be adjusted to make it more readable OR make the default session color upon rename be configurable.

Error Messages/Logs

Steps to Reproduce

1. run claude
2. use /theme command to switch into light theme (or auto in my case since I don't use macOS Dark Mode)
3. use /rename test command

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.245

Claude Code Version

2.1.247

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

Wrong coloring after 1st rename as of 2.1.246:
<img width="539" height="154" alt="Image" src="https://github.com/user-attachments/assets/5558b520-9803-4277-b797-cb00afa0c711" />

Correct coloring after the 1st rename in 2.1.245 and below:
<img width="541" height="129" alt="Image" src="https://github.com/user-attachments/assets/1385f0c4-649e-4e60-b906-d9dee292cbe9" />

I can confirm that on 2.1.245-2.1.247 if I'd had session color set to non-cyan via /color command and then did /rename command then color was preserved as-is (not changed to cyan).