wcag

> This isn't subjective or aesthetics, it's an objective measurement. I’m going to push back against this slightly (I’m not disagreeing that the HN contrast is bad, but I am challenging the WCAG ratios). It’s objective, but it’s not a good measurement. WCAG computes contrast in sRGB, which is not perceptually uniform. As such there are cases where WCAG will give better scores to worse contrast. For example, the WCAG math prefers black text on a medium blue background to white text on a medium blue background, which is the exact inverse to what most people feel is most legible. https://github.com/w3c/wcag/issues/695 It’s the biggest thing I wish would be changed in the WCAG.

Just because you find it readable does not mean others can; also, color contrast is not the only thing that affects readability. In this case, the issue is font weight. Here's some discussion on the issue: https://github.com/w3c/wcag/issues/665

The WCAG also define the contrast ratio in terms of sRGB, which is not a perceptually-uniform color space. This makes the WCAG contrast ratios somewhat meaningless in terms of human visual perception. It's accessibility by edict, not science. There's a rather lengthy discussion of this on the WCAG issue tracker [1]. [1] https://github.com/w3c/wcag/issues/695

The WCAG contrast ratio bit is good. People regularly treat the contrast ratio number as an oracle, but it’s actually a pretty poor scale, and not perceptually uniform. As seen here, a contrast ratio of 3 against a white background is almost certainly more distinct than a contrast ratio of 4 against a very dark background, and may even be more distinct than 5, depending on the device (rule of thumb that I just made up on the spot: TN LCD panels, which mostly means cheaper devices, will suffer more from low contrast on dark backgrounds). For good figures, you need a non-linear perceptual scale, and to consider hue, saturation, ambient lighting (meaning both lighting in the room—good luck on that one!—and on the rest of the surface you control), and the nature of illuminated displays of various kinds. And probably other things too. https://

Relevant GitHub issue: https://github.com/w3c/wcag/issues/695 Also, a related HN discussion: https://news.ycombinator.com/item?id=21357638