Choose a base color, assign or tweak each semantic role, preview the scheme on sample UI, and export the palette.
Named roles like primary, secondary, surface, background, text and accent that map colors to UI purposes rather than raw values.
Role-based colors keep a design consistent and make it easy to re-theme by swapping the value behind each role.
Yes — the builder shows your colors applied to sample UI so you can judge how the roles work together.