Parents both black, chick is blonde. Why?

[NatJ]

This was really interesting as I was not expecting my roo or any of my hens to be hiding such a thing in their genetics. Although now if my older dominant white chick turns out being a hen I probably wouldn't get paint chicks from her and a roo that carries recessive white, would I? Would I need to get a solid black roo with no leakage and all black birds in his family to get paint chicks from them?

If the hen with dominant white does not have the gene for recessive white, I think you could get some paint chicks.

A chick who is pure for recessive white will look white. But a chick with only one copy of the gene will not show any effect-- so it can be black, paint, or any other color depending on what other genes it inherited from its parents.