Tools
Playground
Three tools. All three run on the same colour code CI uses, so an answer here is the answer the build gives.
Theme generator
Put in a brand colour, get a lightness ramp out. Every step is checked against the contrast floor.
Contrast oracle
Measure any two colours with APCA Lc and the WCAG 2.2 ratio, side by side, against the opsinjs floor.
Two-axis lab
Pair a measurement category with a clinical status, and watch the lab refuse the unsafe ones.
Cautions
These numbers describe the shipped presets. Change a token and they no longer describe your theme. Use validating your theme instead.