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I don't think it looks like a blue ring. It's obviously friendly and day active, but unfortunately I can't say which species. If we go on what kind of octos have been on the market recently, it might be briareus (they can adapt and be day active) or something like aculeatus.
I suspect that it is the one from Octopus Gardens that I saw there about two weeks ago. (Esp. since the poster says he's in the 510 area code) It's definitely a male (I saw one shorter tentacle about half the thickness of the other legs) and it was identified as an Aculeatus.
Aculeatus is an interesting species and doesn't grow too large (body maybe 2 1/2 inches, arms about 12 inches. It's day active and very good at camouflage and it can disgard an arm at will to deter a preditor.