My original pet, Rubalooba, was labbed into a Coco jubjub ages ago. He has done the rounds of my friends for the avatar, but is now happily in training for the BD.
I truly believe that he isn't a Jubjub at heart (and was created as a Scorchio - before I knew anything about Neo), but I can't quite decide if I should morph/paint him.
I think that you should keep him as a Coconut Jebjeb because they are very rare and very special pets, there are few like them making them unique, and unique is always a good characteristic for any pet in my opinion
If you don't like him as a jubjub, morph him! He's your pet. You're the one who has the final say on his personality. I don't believe in keeping colors just because they're rare - on a lab pet, I'd give a rare color away, but on a permanent pet, it has to fit and I have to like it.
Never keep a pet because it's "cool" and "rare" and "unique." Keep it because you actually like it on that pet. You say he's not a jubjub at heart--change him. =)