Here are how I have set up some of mine.
Fohat, is there any secret to your color scheme? Are these some keys you want to draw attention to specifically, or are these merely the artifacts of your dye experiments?
OR (hehheh)
Is that color scheme the result of your grandkids spending a weekend with you?
None of my Model Ms have matching keycaps anymore. If anything, kids (and kid fingers) are good at pulling up buckling spring caps, after which the keycap will disappear into one of the toy boxes or be swapped somewhere else, and I have long since given up tracking them so not one of my keyboards has all the keycaps in the same color.