Claude Code ships a dataviz skill with a color validator

Claude Code added a /dataviz skill that checks chart color palettes for contrast before agents write visualization code, per the changelog.

Models get categorical colors and contrast wrong constantly on their own. A chart that fails contrast checks in dark mode still ships if nobody's watching for it.

The skill pairs chart-design guidance with a runnable palette validator. An agent can check a color set for contrast and accessibility in light and dark mode before generating chart code, instead of fixing colors afterward. The changelog says to invoke it before writing any chart code, not after.

That ordering is the whole point. A validator that catches a bad palette after the chart is coded means someone has to notice, flag it, and ask for a rewrite. Catching it before the first line of chart code exists skips that step entirely.

I've watched models pick categorical color sets that look right until you actually check contrast, especially against a dark background. That's a design-eye read, the kind you catch in a glance without needing a tool. A validator that catches it automatically, before the chart exists, is the kind of guardrail that should've shipped a long time ago.

This only works if people invoke it before writing chart code, not after a bad palette is already sitting in a dashboard or a PR. It's in Claude Code's changelog as of July 2, and that invoke-it-first habit hasn't formed yet for anyone.