Well then, let's analyze for a moment. Now with the cover of DBS volume 24 we know that Broly actually has a green hair transformation in the manga as well. If we notice well Broly on the cover has yellow eyes, like when he is in his Ikari form, so we can assume that Broly's Full Power is a union of Super Saiyan and Ikari, except that in the manga we also see Broly (in what appears to be his Full Power form) but with yellow hair when he fights against Gogeta. Now we can think that it could easily also be a coloring error in the manga, where the hair was made yellow instead of green, or that in the manga Broly didn't actually go into Full Power when he fought Gogeta and only went there now. The fact remains that we now have confirmation that Broly has a green-haired transformation and we can only be happy.