Yes I have voted purely on colours. I like Golan's rendition, but it is rather like the Solomon Island's flag.
To be honest, in a universe where 98% of mammals are colour blind, I would not have any colour at all. Colour would be unimportant, but shape, content and meaning would be everything.
Actually, that's an urban myth. Most mammals have some color vision, even cats and dogs (Dogs are duteranopes- they have red and blue cones, but not green ones). They lack the full range of color vision. They have rods and they have cones. It's just they don't have the full three flavors of cones (Red, Green, and Blue) we have, but most have at least one, allowing for some color discrimination. (It's worth noting that Cats can see colors, but generally don't give a ****. Some, however... )
More correctly, with only one kind of cone, they're sensitive to shapes in a wide range (from their rods), and have signalling of the presence of one narrow range of color as a color response. About 0.1% of the population has this defect. Their primary acuity is fine in the main range.
With two, they have a weaker sense of color - some colors we can discern simply don't show up as different. A significant number of humans have this "defect" - about 4% of the population. (With a 16:1 M:F disparity!)
With three, we get "normal" vision.
Birds often have 4 kinds of cone receptors chemicals - RGBU - the U for Ultraviolet.
But there are at least 6 known photoreceptor chemicals that have evolved in various species - and it's been discovered with monkeys that adding a 3rd to the eye gives them "full" color vision... the brain sorts it out in a few days.
So, color is useful... but the question is, "in 300K Years, how many divergent photochromic chemicals will humans on other worlds have radiated to have?" They certainly shouldn't all have the standard Terran 3... but most will have at least 2, tho not always two of our three.
