An ongoing practice in jewelry is to scorch, coat, mix, and generally abuse metal until it gives you the color you want. We’re talking about treatments and alloys, which have wrought unexpected colors from gold, titanium, and platinum, giving retailers plenty of talking points for customers who want the newest and coolest jewels. Great minds in metallurgy have created brown gold using chemical vapor deposition, purplish-blue titanium by way of electrolysis, and blue platinum through a proprietary surface treatment unique to Steven Kretchmer (no surprise there).