Interesting picture, but camouflage is the best mix of art and science. Like SINN outlined, someone in a bunny suit can kick serious butt just by using the proper setting. And someone in Multicam, in the proper setting can still be detected if he's still wearing that cheap cologne blowing in the wind.
+Noise frequency of your camouflage
+Blending of the camouflage colors and patterns
+Human outline must be broke to reduced shape reconition
+State of awardness of the people looking for you
+Shadows
+...
Look at this excellent document on Wikipedia:
http://en.wikipedia.org/wiki/Camoflage
and there's a lot of links to MARPAT, CAPDAT, DPM...
But, Multicam still kick ass.
A+