The problem is grey usually means "disabled" which also implies that data may be stale.

As it is you can set a text box read only but active, but it does waste time since it doesn't code that it's not interactable visually (i.e. you have to make up a scheme).

Basically it would've been nice to have a consistent background color or other visual cue which says "this will update, this is live, but you can't type here".