In that particular cross the white was obviously carrying the E (extended black) and the Bl (dominant blue) genes. Neither of those traits could have come from the wheaten side of the mating. There is no guarantee that other white birds would be carrying those particular genes, the only way to find out would be to make an experimental mating. The resulting offspring would by hybrids, because they would be split at the e locus. That means that mating the offspring back together would yield various combinations. My recommendation? Find a black or blue bantam cock with the features you are looking for and mate them into your own line. I have several nice blue and black cockerels coming along, and most of them will be available after the national meet in Sedalia. I expect that others will have those colors with nice combs as well. It is a common misconception for folks to think that because their sample of a variety has a particular fault that all or most of the others in that variety have the same fault. Not true. On the other hand, I can understand that you may not want to bring in outside adult breeders for potential health reasons. Chicks from a better line would be a safer way to go.