This image is derived from the Glowing Cells image, which is already constructed to be fully uniform throughout the RGB spectrum.
The pixels in the original image are recursively partitioned into 8 equally sized groups, depending on whether their colour is closer to pure black, red, green, blue, cyan, magenta, yellow or white.
The partitioning acts as a binary search of the unique colour to associate to the pixel, at every iteration reducing the range of each component of the colour by half.
Image Licence: Public Domain (CC0).
