He may still be useful if you have any overmelanized pullets. Like Keith said in an earlier post, overcolored cockerels can balance out the excess black on overmelamized hens to put better copper in the hackles of the female offspring. The excess black on the hens will balance out the excess copper of the cockerel at the same time. If you have room for several different breeding pens that is. We keep extra cockerels in 4x4' stag pens. We also use the small 4x4 pens to single mate as well.
I'll have to see what I can do for separate breeding pens. My girls are too dark but That's why I'm confused as to how I ended up with such an over colored boy lol