Spirit says: The Trek norns, which are norns that spend their childhood as lavender Purple Mountain norns but when they grow up,they join Star Fleet a.k.a Norn Fleet (uniforms appear at adulthood).
Yes,I know it's weird, but heck, we only live once and I've been in a goofy mood lately. :)
Plus when bred with regular norns the babies they make are a real treat,the sprites mix at random and if the regular norn has any PM sprites you won't know until adulthood what they will look like, it'll be a surprise since they look alike until they grow up.:)