I made this very blurry radial illustration to test the easiness of getting the blend effect. It appears that the sharper the central fixation point and the softer the zones to be fused around the center the easier it is for the eyes to fixate. Perhaps it is because there is no distraction from the center point so it is easier to fixate the eyes and there is no distracting detail in the blurry regions to confuse the brain. This is the exact opposite from the massive amounts of wiggle lines in the sunburst design which were much more difficult to fixate upon and prevented fusing of the images.
The red-green blend with white spacing produces a blend that is a lighter silver color than the green-red radial blend which tends to produce a lead color. That would seem obvious but we must be careful here with obvious conclusions because the flashing between red and green in the center ring going the opposite from the outside field isn’t to be expected when the colors being presented to the eye are exactly the same.
It takes a minute of watching to get this reversing effect. After a minute the eye starts developing color fatigue effects which are noticable in the halos developing around the edges of objects. This effect isn’t so noticable around the soft edged objects. An interest way to effect this affect, or is it to affect this effect, is to move one’s head around while keeping the eyes fixed on the central dot. I suspect that it is the rhodopsin, the visual chemicals in the eye itself, which creates these sloshing halos. The visual reversals from the blending of the two different eye images must be created in the brain.
Your mind is a wonderful place to visit.