I've finally managed to get relative CSS colors documentation published on MDN. This was a complex beast to tackle, and I'm proud to see it out! Get started at https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_colors/Relative_colors; also see the color function pages to find out what relative colors look like in each.
Using relative colors - CSS | MDN

The CSS colors module defines relative color syntax, which allows a CSS <color> value to be defined relative to another color. This is a powerful feature that enables easy creation of complements to existing colors — such as lighter, darker, saturated, semi-transparent, or inverted variants — enabling more effective color palette creation.

MDN Web Docs
@chrisdavidmills Not very metal examples are they? 😂 You so should have based everything on black, and reasoned that 'background-color: lch(from black calc(l - 20) c h);' was like _really_ black. 🤘
@pete @chrisdavidmills "black for the sky, black for the sea, all black..." https://www.youtube.com/watch?v=XAERxf4yYaw
Very Dark Almost Black - Johnny Nice Painter, The Fast Show. Remastered [HD]

YouTube
@patrick_h_lauke @chrisdavidmills Haha! I didn't even need to click the link to know what that was gonna be.
@pete I'm the prince of fucking darkness, don't you know? ;-)
@chrisdavidmills Someone talked of Dark Satanic Mills in a call the other day and I got all sentimental! And unrelated to that, was also remembering us watching Cheryl and PJ's band before hanging out at his brother's rock'n'roll pad surrounded by MTV awards and the like. #GoodTimes
@pete Yup, good times man! I did enjoy the Apress days. What are you up to these days?
@chrisdavidmills I work as a jack of all trades on a training, simulation, and AI testing platform for radiologists: https://www.raiqc.com
RAIQC