A very interesting website that gives an approximation of where you draw the line between blue and green, which varies widely: ismy.blue . My results (click for larger view):
"Your boundary is at hue 176, bluer than 68% of the population. For you, turquoise is green."
Trying to interpret this is interesting; how much of this is actually a difference of perception, and how much is a difference of classification? I'm pretty sure my results are partly classification -- I think I tend to treat green as a 'messier' color than blue, so am more likely to treat marginal cases between them as green than blue, being stricter about blue classification than green classification -- but perception certainly is involved, and of course there is the question of how much the classificatory difference is rooted in perceptual difference. There are also issues of classifying in vague situations. For instance, I don't actually find the pure hue turquoise to be strictly green; if bluish green is more green than greenish blue, you could say I find it to be bluish-greenish rather than greenish-bluish. Most of the choices in the quiz I found very difficult to make because of this. (Actual turquoise gems, on the other hand, I usually find definitely blue but sometimes definitely green, and almost never ambiguous.) Comparison is also a relevant point. There are certainly circumstances in which I would set the line further to the left or to the right; if you asked me a choice between blue and yellow, for instance, I would classify as blue hues that are well into the green on this particular chart.
