Why is gold such a richly colored yellow compared to other metals? Gold is very efficient at reflecting longer wavelengths (yellow through red), and poor at reflecting short wavelengths (violet through green). Gold is very efficient at absorbing longer wavelengths (yellow through red), and poor at reflecting shorter wavelengths (violet through green). Gold is very efficient at reflecting shorter wavelengths (yellow through red), and poor at reflecting shorter wavelengths (violet through green). Gold is at its brightest rich yellow when it is alloyed with copper, which makes it reflect more yellow wavelengths. Gold is at its brightest rich yellow when it is alloyed with silver, which makes it reflect all wavelengths more