What happens when every color Pearl fuses together.

At Blue Diamond's court, you can see a Gem who might have been Lapis. The silhouette was pretty recognizable, and the Gem was shown to be on her back (all the silhouetted Gems still had their gemstone locations pointed out), so maybe this was a common style among BD's immediate followers.

Yellow Pearl's hair is supposed to look somewhat like Yellow Diamond's, since it looks like it's pretty much confirmed that Pearls can be specially made for whomever can afford to own one.