Haven’t been keeping up with the BC morph world. Any of these morphs particularly known to really hold on to their juvenile “look” as adults?
Few retain the same look into adulthood. You’ll find color shifts in one direction or the other.
Animals that hold onto their basic look off the top of my head would be sterling, Motley, Inca, Scoria. Ones that stay basically like the youth colors/look but do have a change for the better, would be jungle, labyrinth.