Remember that time when you sipped some herbal tea and thought, "I really want a pink gold ring
?" Yeah, that was some good tea alright, but the brainiacs at the University of Southampton have actually found a way to achieve this potential fashion trendsetter. The idea is simple: rather than coating metals -- especially naturally colored ones like gold and copper -- with paint, these folks alter their color by using an ion beam to carve fine patterns that are smaller than visible light's wavelength. The resultant metamaterial
dramatically boosts the metals' light absorption efficiency, thus reflecting a different color depending on the pattern's radius and etch depth. So for instance, gold can reflect colors ranging from orange to red to green to brown with its ring pattern etch depth ranging from 85nm to 205nm, respectively. See? We told you it's simple, but there's also some visual aid after the break to wrap up this science lesson.