trimfox ships grayscale — that's the stock look, fixed on the left as your reference.
Everything else here is optional: pick a base color, or dial hue + tint strength, and
compare your palette (right) against stock. It drives the exact tinted.css oklch() formula.
A grey, or tint strength 0, is grayscale.
user-overrides.css (gitignored, survives upgrades) with @import 'palettes/tinted.css'; at its top. Stock needs nothing.