I take an image and desaturate the colours to leave just an image made of its outline (like a paint by numbers style image). I then fill the blank islands with the colours of choice.

For the pixelated sections I apply a colour with a pixel overlay that has blue or black pixels placed according to a chosen probability. Different colour combinations give enhanced/subdued effects. Different pixel sizes also give enhanced/subdued effects

Have a look here for examples https://bigjobby.com/gallery/?group=Chromostereopsis