> Our new documentation system is built upon MkDocs, with theming designed to match WebKit.org’s visual style. Slight omission there that it's using mkdocs-mat

> Our new documentation system is built upon MkDocs, with theming designed to match WebKit.org’s visual style. Slight omission there that it's using mkdocs-material for the theme, and not a theme they designed. mkdocs-material has built-in support for custom colour schemes which is how they've achieved the WebKit visual style.