Radix Colors ships each accent in 12 steps (1-12, light to dark), each with a paired alpha version (1A-12A) for transparent overlays. The advantage is composability: an `accent.6A` overlay on any background produces a consistent perceived darkness across hues. Catalogued sites in AI2 Design that use Radix patterns (Blackalgo, Lightdash) inherit this discipline — visible in the brief's `colorPhilosophy.usage` array.
Glossary · color
Radix Alpha-scale Palette
Radix Themes' 12-step accent scale with paired alpha-channel tokens, designed for perceptually consistent overlay effects.
External reference
Radix ColorsCatalogued examples
2 catalogued sites demonstrate radix alpha-scale palette in production.