I still think there's something odd going on here. The pixels should only be blending between the two colors and the pixelation seen on the left side looks correct. The pixelation on the right should more or less be a mirror of the right side.
In other words, it should be consistent all around the image and the pixels should blend between magenta and blue, not blue and less saturated blue.
Also, there is slight 'fade' within the darker blocks, which shouldn't be happening. Here's a Exporter Render that shows it a little more clearly.
I did a different render early this morning that showed an even more gradual L-to-R fade within the dark blocks. I'll see if I can reproduce that later.