@chrisdavidmills Sorry reread your message - concrete example:

I get a hex value out of some random color picker: #8EAAA5

I'd like to use this colour, and get some darker versions of it as well.

So (hopefully I've got this right), I could do it like this:

```
--theme: hsl(from #8EAAA5 h s l);
--darker: hsl(from #8EAAA5 h s 50%); // #6E918B
--darkest: hsl(from #8EAAA5 h s 35%); // #4D6661
```