The first example of how HSV's hues have different perceived brightness is an interesting topic. Some researchers have been looking into better grayscale filte

The first example of how HSV's hues have different perceived brightness is an interesting topic. Some researchers have been looking into better grayscale filters that could pick out colour distinctions better, too. PDF, in case you're interested: http://www.cs.northwestern.edu/~ago820/color2gray/color2gray.pdf http://www.cs.northwestern.edu/~ago820/color2gray/color2gray...