Since we're talking about colors:
How does the poison arrow frog communicate to animals that are color blind that it is indeed poisonness?
We know animals avoid brightly colored animals as food in the wild, but not all animals can see color. If it is indeed only a matter of the brain, how come these other brains can preserve their own lives?
Give me a specific example of an animal that responds to color without being able to see it? My first impression is that you are making this scenerio up.
Presumably it fails to communicate its unpleasantness to every conceivable predator.
This is a common anti-evolution argument that goes as follows, "Since adaption 'x' does not work in every situation faced by species 'y' evolution is a crock...". The argument misses the point that the benefit of the adaption is still apparent in other situations, and as long as the cost of the adaption is less than its overall probabilistic benefit natural selection will tend to preserve it. Nature doesn't insist on perfection, most of the time good-enough is good-enough.