blue... well, blue assesor comes to mind, but I'm not sure if they'd get big enough.
There's a few types of dwarf angels, check out liveaquaria. They may nip corals.
There's chromis, but they'll be eaten or if you get a group, they'll kill each other after a year or two.
Damsels might be fast enough to keep from being eaten but probably not.
And there's wrasse which come in every color imaginable. That's probably your best bet for a blue fish that's reef safe and won't be eaten, IMO.
There's a few types of dwarf angels, check out liveaquaria. They may nip corals.
There's chromis, but they'll be eaten or if you get a group, they'll kill each other after a year or two.
Damsels might be fast enough to keep from being eaten but probably not.
And there's wrasse which come in every color imaginable. That's probably your best bet for a blue fish that's reef safe and won't be eaten, IMO.