This article puts the description of it at the bottom, but APCA Contrast—which is the readable contrast test in the WCAG 3 Draft Standard—is much more fair to some colors than WCAG 2.1's Contrast Ratio was.
APCA works great, but it has a very weird and restrictive license. Before you consider it for anything you should probably take a detailed look at that and consider if it's really usable for you.
I am sorry about the licensing issue, it is only temporary during the public beta. And I am providing some exceptions, if you need, send an email to legal@myndex.com
Just can't do an MIT type license right now—and really there's no generic one that really suit what we need right now, so we're working on such a license, one that is reasonably permissive yet prevents some of the issues we've run into. I.e. like with bad actors incorrectly modifying, or reverse engineering and doing so wrongly, or taking it to the cantina at Mos Eisley...
Good reading for the color theory behind perceptual contrast: https://www.smashingmagazine.com/2022/09/realities-myths-con...
And a distilled description of APCA: https://typefully.com/u/DanHollick/t/sle13GMW2Brp