When building a multi-brand system, sub-brands often feature radically different primary colors (e.g., Brand 1 is dark Navy Blue, Brand 2 is bright Lemon Yellow).
If your primary button simply places white text on top of the primary color token:
To solve this, design systems introduce a paired contrast token:
color-primary: The background color.color-on-primary: The mathematically computed high-contrast text color (#ffffff for dark primaries, #000000 for light primaries).Level 5 · Auditing & Multi-Brand Theming