let us customize user_message_style

What variant of Codex are you using?

cli

What feature would you like to see?

I want custom coloring for user_message_style, the default is pretty hard to read in my terminal (see screenshot). Personally I want to set it to a cherry blue background with white text, so I can more easily spot my own writing when scrolling.

<img width="491" height="278" alt="Image" src="https://github.com/user-attachments/assets/e1b89863-9edd-42c3-a2e5-26e62037b7c5" />

Additional information

thanks guys