On: Uchū – Color palette for internet lovers

[NetOpWibby]

> If you want more granularity (read: opacity), you can call the raw version of the color (append -raw to the variable name) which will return the OKLCH values so you can do something like this: oklch(var(--uchu-gray-1-raw) / 40%).

via https://github.com/NeverCease/uchu/blob/primary/documentatio...