As came up in the Discord here first the issue, and a potential partial solution:
Users would love to have a triad system, as does for example Army Painter Fanatic. A triad is basically a guide for users, that don't want to explore mixing too much. This can have various reasons, from color blindness, the needs of army painting, decision anxiety, or plain inexperience.
As your first wave will not contain triads, I'd propose a guide for users to gently give color theory based suggestions to predictably mix Colors. While still needing to mix, it might be a good help for many and give a first intro to color theory. It also builds on the availability of a broad spectrum of pigments in Ultracryl, and many single pigment paints.
The guide could contain:
- complementary paints, maybe even show on your color wheel how they connect, show photos of different mixing ratios. This basically gives a "shade" to "midtone" guide
- Highlight suggestions, white, buff white, bright yellow, bright blue, fluos. I don't have a good idea on how to couple highlight color to "midtone" in the same way as for the shade though
Advanced guide, builds on the complementary experience:
- Nice triad triples for good color schemes, with the idea to for example desaturate two and have one saturated main color
- Give different palletes ideas for mixing everything: Yellow-Red-Blue (classic), CMYK (modern), Zorn (limited, painterly).