`data-identity` on the root swaps the identity tokens next to light and dark; a head script applies the stored choice before first paint and a labelled switche…
Who: Teams that want to change the whole look of an app, or offer a choice, without touching components.
What:data-identity on the root swaps the identity tokens next to light and dark; a head script applies the stored choice before first paint and a labelled switcher or touch picker lets people choose.
Use when: To rebrand or offer several looks from one set of components.
Avoid when: For a single fixed brand — edit the base tokens in styles.css instead.