it's a neat experiment but I think it's ultimately flawed because color is usually perceived in context, and depending on context I could easily see anyone reinterpreting the hues they labeled "green" in this test as blue, and vice versa.

EDIT: in general, blue is a pretty fascinating color. yes, many cultures have a somewhat blurry distinction between blue and green. Some others seem to differentiate shades of blue that others don't (i.e. in Russian "голубой" and "синий" refer to distinct colors but in English those would be just shades of blue). I guess there's something about photons in that energy band that messes with perception. https://en.wikipedia.org/wiki/Non-photo_blue