Most mammal predators have a pretty good sense of smell, and scent is likey to be their best clue when hunting dinner. Most birds (vultures being an exception) do not have a good sense of smell, but they ALL have exceptional vision. Much broader spectrum (into the UV), and what some call an additional dimension than what humans have (diferent types of receptors in the eye). I don't know that we can adequately determine what would be the best camouflage--simply because we do not see in as many colours, with the focused precision or as broad a spectrum as hawks and other bird predators. All that said, different environments would call for different types of camouflage.
If you look at soldiers' camouflage uniforms, there are a variety of camouflage patterns, and depending on where they are deployed, they will have different types of camouflage paterns. Jungle camouflage does not provide any visual protection in snowy conditions, and arctic camouflage would not providew protection in a woodlands. Green, grassy meadows would need a far different visual protection than would sandy desert.