Green vs. blue: the same, or different?

Via JohnnyO at Burrito Justice comes this puzzling Wikipedia article on green vs. blue and the revelation that many languages do not make a distinction between the two but rather use a single word to describe both. One such language is Vietnamese, whose speakers – when forced to distinguish between the two – apparently call one shade of this color  ‘leafy’ and the other ‘ocean’ to create a distinction.

I was absorbing this weird bit of information when it occurred to me that I’ve been inadvertantly field-testing this phenomenon for years now. Prague has a large Vietnamese contingent (a trend that dates back to the days of Communist brotherhood) who run a great many of the local convenience stores. I frequently buy gum at one such store near my flat. This purchase requires pointing at a wall-mounted rack of gum behind the counter and saying, “Blue Orbit, please…  no, blue… thanks” to the Vietnamese counter person. So far, I haven’t noticed anyone mistakenly clutching at the green gum instead, although I’ll be paying far more close attention from now on. In particular, I’ll be looking to see whether the green and blue Orbital varieties have been arranged at opposite ends of the rack, so as to minimize potential ambiguity.