Sounds right.As I understand it probably the white bird is black under the white gene... and now all chicks carry a recessive white gene. So if you cross back to white parent you could get white, black, or blue (if you use blue offspring), cross the f1s all three colors possible but if to blue parent, you should get blues and blacks that may or may not carry white gene. I am no expert on this but I think this is what would happen.