heh. that's cute. i knew karl back in the day. you could also say that it's the colour of the microwave background, which dominates the radiation in the univ

heh. that's cute. i knew karl back in the day. you could also say that it's the colour of the microwave background, which dominates the radiation in the universe (it's the "glow" left over from the big bang), however that's cooled so much that it's effectively black. i'm not sure how they defined average to avoid coming out with black from that. would be worth checking the paper...