Agree on the GBP. There are so many morphs of zoas that it can get really confusing. From what I understand the common name thing is basically limited to the hobby since there are really only a few different kinds of zoanthids in the real world by DNA classification. Protopalys, parazoanthus, zoanthus, palythoa and so on.
But naming the different morphs gives us something to do and makes the collection of zoanthids much more exciting.
To get into arguments over what is what by common name, not saying there are any arguments going on here, but everyone has seen it happen at least one time, is baseless since all zoanthus are basically zoanthus and all palythoas are basically palythoas, etc.
If a person wanted to they could call that morph of zoanthus you have there Rainbows, and no one could really say you were wrong, except in the world of reefkeeping hobby.
Look at all the different vendors calling a specific morph by different names.