So there’s no such thing as "red with a little green" -- there’s just a less intense red. The brain physically cannot see "greenish-red" because the filter remo

So there’s no such thing as "red with a little green" -- there’s just a less intense red. The brain physically cannot see "greenish-red" because the filter removes that information. Under ordinary circumstances this is true. However, it has been shown that the human brain can be made to see reddish-green, yellowish-blue, etc. Scientific American published an article about this strange hack of human visual perception just last year. http://www.scientificamerican.com/article.cfm?id=seeing-forbidden-colors http://www.scientificamerican.com/article.cfm?id=seeing-forb...