black ones, gold laced Polish cross; gold ones, Dutch bantam cross - and how big is your brother? If he's young and not too big, that could be a pure Dutch of mixed variety or a Dutch/OEGB cross; hard to tell without an accurate size scale
ETA: Just saw where you said pea comb ... is it pea or rose? can't be pure dutch, but could be sebright/dutch or sebright/oegb (although the latter usually has white legs). the cross sometimes makes the rose comb look like a pea comb