Pseudocorynactis caribbeorum, or ball anemonies I believe. They are cool under actinic or moon lights. I found that they sting other corals around them and prevents them from opening up, like my Zoa's. I get rid of them or move them to another location as they near my coral. Briliant color under the blue lights however. The bulbs are sometimes different colors. Resembles a little firework.
The expanded polyp of
Pseudocorynactis caribbeorum. Note the orange ball- like tentacle tips for which the Orange Ball Anemone is named.