[mbfg]

Is that true? Yellow/Orange/Red are perceived as 'danger' colors. Is that just a made up association in our brains, or do we see yellow/orange/red more readily? If you flashed a bright orange billboard in front of a chimpanzee, would you get a different reaction than if you flashed one that was dark blue?

[dismantlethesun]

Orange and dark blue are names we give to perceived frequencies of light.

Dark blue isn't really any 'darker' in terms of energy content spectrum than orange is, its our brains that have evolved to make this association that X spectrum is dark and Y spectrum is bright.