Buff Sussex/pure white chicks

[Melx]

Hi I am fairly new to breeding chickens,I have 5 hens and 1 cockerel.I hatched the eggs in an incubator and 3 chicks are pure white,does this mean they are impure or a 'sport' ?

 

[Justso]

Sorry melx, I'm having a hard time following.
Did your hatching eggs come from buff sussex that you have, or did you hatch out what you thought was buff sussex chicks from someone?