A lot of research has actually been done on how humans and individuals perceive colors and tons of statistics exist. The results was the creation of many perceptual color spaces such as XYZ and CIE L<i>a</i>b that more closely match human perception axes of lightness, blueness and green-red-ness.<p>While it is true that our perception differs, we mostly share the same attributes close enough that we can fix standards (except for different cases of color blindness). For instance, we physically perceive blue, yellow, green and red as distinct colors and the rest is a mix of those (magenta being kind of a special case).<p>What we see as pure blue is actually a precise color point defined by how the eye physically perceive light. Reds, yellow and green are a little bit more fuzzy because they depend a lot on the ratio of red and green cones in our eyes so the brain is taking a little more liberty there.<p>The major difference between individuals is how precisely they can differentiate two similar colors.<p>I think the problem with CSS is they tried to qualify way too many colors with subjective terms instead of sticking to a clear and predictable system (either mathematic or designed), even if imperfect.