Robert, have you seen the article in this quaters Reef hobbist, about the blue horents. They look almost exactly like the blue steel, and if you read the article http://www.reefhobbyistmagazine.com/archives/vol_3/issue10/pages/11.htm you will understand why.
When they were orginaly brought in they were more blue, only for some ppl did they develop the purple coloring, which is what made them vavulable, the orginal colonies were not that expensive as they had a tendicy to die off in ppls tanks and were brought in in abundance, however the guy that coined the name Purple hornets said his only turned purple under intense MH lighting