Design tokens: ability for one ‘colour style’ or ‘font style’ to reference another (a.k.a variables)

Feature request:
The ability for one ‘colour style’ or ‘font style’ to reference another. (a.k.a. variables)

When building a design system with design tokens, I would love to have a base token (e.g. green-100) and then an alias token (e.g. color-action) but have the latter reference the former so that if the former changes, the latter is also updated.