Here is a example of what happens to buff when you have to cross out to another color.About 7 years ago I bought 5 buff bantam chicks.Raised 3 to adult.All cockerels.So I crossed to bantam whites based on black.I had no wheaten bantam.Which is the go to cross most used.Note group pic.Hens are 1/2 white.At that point that rooster is 1/2 wheaten.I bought him.By that time I no longer had a pure buff rooster and could find none for sale.So I have been remixing these since.There is a pullet that looks buff but has black in wings when spread.The same for the cockerel.The last cockerel is older but has black in the tail and is too red.I switched roosters to get the younger birds.I have made arrangements for a pure buff cockerel.I have picked up better egg color and vigor with the cross.Still it has been a long road back to good buff color.So crossing colors is often a long road back.Not to be entered into lightly.