Nothing new under the sun! This is one of the 'diode' butterflies. The metallic sheens are reproduced by fluorescent pigments placed over reflective mirror-like structures. The overall effect is to intensify the colour. The latest LEDs - light-emitting diodes used in computer screens use the same idea. See the following url for more details http://news.nationalgeographic.com/news/2005/11/1117_051117_leds.html