Converting CSS Lch to RGB

Question

I wanted to convert a CSS Lch color string like:

--my-color: lch(20% 8.5 220.0);

To an RGB hex code. I tried using tools like chroma's Lch parser, but all of them seem to use absolute values for the first ordinate (the 20% in my case).

Is there some standard way to convert that 20% into the lightness values used by most Lch conversion tools?

Answer 1

The w3c is working on a draft and there is example code in javascript attached (it's a bit too long to post here and you'll need higher math to do that (at least sin and the power of 2.4).