Bit disingenuous of Hublot to say there's anything new about red gold though - it's been around for centuries. Nothing to do with platinum either, it's about increasing the amount of copper in the alloy compared to the typical 25% of rose/pink gold. Why would a grey-silver metal make gold more red? Answer, it wouldn't, but it's what Rolex uses in its trademarked Everrose gold to make it more blush pink and I imagine that is what Hublot is skating around stating outright.