Hatched a black chick when the parents aren't?

[AtlantisPeeps]

So this chick hatched today. The mother is a lavender Orpington, Diva(I saw it come out of her rear so I'm 100% sure) and the father is a red sex link (I'm also 100% sure because he's my only rooster). It came out dark grey or black??????? With a white underbelly and white wing tip????? I don't even have any black chickens! I hatched two other eggs from Diva and the babies are almost white with a few black dots. I don't understand? Can someone enlighten me?

Here's the chick in question-

Here's one of the siblings (same parents, and the third sibling looks like this one as well. White-ish with 3 black dots on the back and head)

 

[FridayYet]

A lavender bird is really a black bird with a recessive dilution gene. You need to breed a lavender to another lavender or to a black split to lavender to get the lavender color. With anything else, the chicks can be black.