Two source-of-truth checks the DOM-walk advisory can't do reliably. (1) Static source lint — any base rule that sets color: var(--cs-color-brand-umber) on a themeable surface (surface-*/transparent) MUST have a matching [data-theme="dark"] override, or umber goes near-invisible on dark (the nav-item/secondary-button class). (2) Token-pair matrix — every semantic text×surface pairing is scored (WCAG) in light AND dark straight from tokens/tokens.json; no DOM, so no false reads. Screen-template inline umber-on-header is listed as review (bg can't be known statically). window.__contrastguard.pass must be true.