I'm torn getting a cherry profile for two-tone but I don't know if it will be compatible to my Varmilo stock keycap.
If you have white Varmilo caps, then you can try dyeing them yourself.
PBT can be colored very easily with nylon dyes. (Dylon MultiPurpose, Rit, iDye)
I was playing a bit with Dylon:
Full process:
http://imgur.com/a/EovomI wanted light blue mod keys, but I messed up the cooking time, PBT needs around 10 minutes.
(Earlier I tried to dye an ABS set, which was barely colored after 30 minutes, even after I added 200ml acetone as thinner)