A while ago I spent some serious time making myself some reference colour chips from several Premo! shades. I did them as Red / Yellow / Blue wheels and used various colours for the RYB values.
To the resulting hues (I did a 24 chip wheel) I added various amounts of white, grey, black, ecru and beach (white+ecru). In the end I ended up with literally hundreds of little colour chips. I strung them on cord and they’re in my studio.
I finally buckled down and wrote the recipes out, as close as I can get them to show on monitors, and put them up as pages in my Learn section. Enjoy!