I'm 100% sure that this is what we call a Rainbow Wrasse.
A search on google images will confirm this, but even from what I remember out Rudy Van Der Elst's book, this is certainly a Rainbow Wrasse.
I've only ever seen one, not being a diver it makes it harder, but I saw one swimming on the beach side Durban's North Pier, before the whole revamp thing.
I tried to catch it(obviously), but it didn't want my piece of sardine...seems they like cammo worm!!!