Object name in red

I have some objects that seem to be working fine but their names in the hierarchy appear in red. I think this has something to do with deleting prefabs… Is this something that is warning of trouble? Is there a way to reset them to the standard black?

Never happened to me, want to know though

Prefab instances become red when you delete a prefab and you have the prefab instanced somewhere. Unity keeps the last state of the prefab instance though, so it is fairly harmless.

Harmless is good. Thanks.