Persistent default session color (settings.json key or launch flag)

Feature request

The /color command sets a session color, but it's session-scoped only — there's no way to make a chosen color the default for future sessions.

What I'd like

A way to persist a default session color, e.g.:

• a sessionColor (or similar) key in settings.json, and/or
• a --color <name> launch flag that an alias could pass.

Current behavior

/color orange works per-session, but every new session resets. Neither settings.json (per the full settings schema) nor claude --help exposes any color option, so there's no alias or config workaround.

Why

Persistent per-project/per-machine color is useful for visually distinguishing concurrent sessions at a glance without re-running /color each time.