Yes, they are. In the mission "Return to Babel" you travel back in time to the USS Enterprise during the events of "Journey to Babel", which is where the Violacean delegate appears. The word is never spoken out loud, but I imagine it to be pronounced "Veeolaseean".
In the same mission, the hooded aliens are called "Zambeans", which is hopefully not because one of them was played by a black guy.
In my TOS novels, I referred to the purple folks as Icorians, because Bob Greenberger used the name for a purplish-gray species in SCE: Troubleshooting and I figured they might be the same species with different skin tones. I referred to the tall hooded species as Makusians, from Makus III, the Enterprise's destination after "The Galileo Seven."