I think duochrome eyeshadows are so beautiful, as the colour of them changes depending on the light or base used under them. An example of one is the eyeshadow I'm wearing in this picture which is a colour from Wet n Wild's Comfort Zone palette, but this colour can also be found in 'Club' eyeshadow and 'Blue/Brown' Pigment, both from Mac, and also a pigment from Makeup Geek called 'Insomnia'.