Mystery yellow chick

[schambo]

The hen is Blue Buff(Columbian)in color, most likely Wheaten based. Both are Dominant.
Lavender would act as black, that's correct if he were the father, so the mother would make either leaky black, or blue Incomplete Columbian chicks.

That hen, & Blue Copper Marans would produce Blue, Black, or Splash Birchen chicks.

Is the chick completely White? Or is there some other color on the back?

The chick is white (yellow), and has a few dark splotches on its back (can’t tell if blue or black)

 

[MysteryChicken]

The chick is white (yellow), and has a few dark splotches on its back (can’t tell if blue or black)

Are they like broken stripes?
Pictures if possible of the back?

 

[schambo]

Splotches

 

[MysteryChicken]

Splotches
View attachment 3781083

I'd wait till it feathers out.
Could be a Splash chick, but could be something else as well. Looks both White, & yellow with some black. Haven't seen that with Wheaten chicks.

 

[schambo]

At least one is part silkie! I usually keep my silkies separate from my regular flock, but Peanut here has 9 toes (4 on one, 5 on the other), so it looks like Muffin has some ‘splaining to do. He’s a black silkie with quite a bit of reddish leakage, so the black must be covering something that would give this colour with a wheaten hen (partridge?)