I have two yellows and one blue, All came from BlueZoo.
They don't shoal but will hang together as a loose group.The two yellows stay together and the blue keeps to himself, he is also more outgoing than the yellows and has grown to be slightly larger, all are pretty delicate and I have never seen any of them harrass any other fish.
I used to keep them in a 65 gal with mellow tankmates and they were out all the time. I have since taken down that tank and they are now in my 210. I never see the Yellows when the lights are on aside from looking in their hiding spot in the rocks, the Blue, allthough visable stays in a back corner of the tank and does not venture out. During the mid morning when all the other fish are still asleep all three are out and about and can be seen with ambient room light, once the other fish start to come out the Assessors are gone.
I highly reccommend these fish and most picture don't do justice to the subtle greens and reds in the yellow ones. I honestly don't care for the color of the blue, its almost a slate dull blue.
It would be a waste to put them in any tank unless its totally peacefull else you won't get see them. Mine are in my 210 simply because I could not find a suitable home for them at the time I took down my other tank. They are healthy and apparently happy in the 210, I just don't get to see them anymore.
Whose picture is that. Its a very good one, it reveals the reds but not so much on the green. I have a bunch of pics but none that are anywhere near that good.