The part of my brain that never stopped playing Tetris notices that if you had striped the color variations left to right instead of top to bottom you’d have a more uniform color variation. And if you’s put half the dark and half the light on each side then the gradient would look more purposeful. But you also probably should have printed 2x as many keys and split them up for making two copies.
Keen eye, initially I did sort the right split from left-to-right. But also over time the fat from the fingers affected the color as well, so I figured it's a loosing battle anyway. I'm waiting for a white colored MJF print, which should eliminate these color woes once I figure out the proper dimensions.