Well, the gold form of Heros efasciatus(no longer Heros severus) is supposed to be the colour mutation of the green. Though because the history of the gold form was not recorded or anything and it was so long ago, some people speculate it may be a hybrid though I do not believe so. The ones in your pic looks like a cross colour between both, so maybe one parent or grandparent or great grandparent was a green and the other a gold. I foresee no problems here.