I think that gold is used as much or more for it being a precious material as it is for functionality. I'm sure the color difference between a light yellow brass and gold isn't going to be that great. But the brass just doesn't have the prestige or status that gold does. I think this is along the same logic of using mammoth for grips. For me personally, I can't see any logic in using that material. In most cases, a nice figured piece of wood looks much better than any piece of mammoth. But that's not the point of using mammoth. It's because it's supposed to be rare and therefore expensive. It's more of a status thing than a functional thing. For that matter, I'd never have a set of polished mammoth or wood grips. A grip is called a grip for a reason. It's supposed to help you hold and maintain a grip on the pistol. Checkering or stippling helps you do that so much better. But this is also why polished grips tend to be on barbecue guns or mantle pieces rather than functional firearms.