The WCAG luminance formula (relative luminance in color science terms) has perceptual mid gray at 0.18, not 0.5.
re: just change APCA contrast target, that's separate from the Not Even Wrong stuff in the article. I didn't mean to imply APCA is wrong to say you need less contrast, but rather, that the article is wrong to conclude white has more contrast.
re: just change APCA contrast target, that's separate from the Not Even Wrong stuff in the article. I didn't mean to imply APCA is wrong to say you need less contrast, but rather, that the article is wrong to conclude white has more contrast.