[wodenokoto]

The whole point of asserting where your border between green and blue is, is to ask about colors that are in between the two. It doesn't make sense to ask is RGB(0,0,255) blue to you? Well, unless you are color blind it is.

[isoprophlex]

Of course, that's clear as day; the idea is to reset your presumptions from the previous trial and sample the ambiguous colors in a more consistent way, by priming you from the extreme ends of the green/blue scale.

See it as a way to avoid perceptual hysteresis.