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 prim

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.