Nuno Pinheiro is a artist, working among other things on KDEs icon set. We discussed on the openSUSE conference 2010 about the missing ICC profile mime type icon, and he created a simple, and very well recognizable SVG icon. Personally I like it much.
Many readers might not know what this graphics actually means. This often horse shoe called shape is from a CIE*xy diagram and represents the range of human visible colours. The border represents the spectral colours, which are highest saturated to our seeing. One can find lots of scientific colour diagrams, based on the CIE*xy horse shoe. So it represents as well human vision and a scientific approach of colour reproduction and matching. Of course without Nuno’s artistic interaction it would be half of the fun.