- From: Chris Lilley via GitHub <sysbot+gh@w3.org>
- Date: Tue, 14 Jun 2022 18:21:16 +0000
- To: public-css-archive@w3.org
To take one example, in [The Science of Color & Design](https://material.io/blog/science-of-color-design) by James O'Leary discusses their hybrid color model HCT which uses the L axis from CIE Lab (Tone) but Hue and Chroma axes from CAM16 (Hue, Colorfulness). Contrast is then the difference in Tone: > The HCT color system makes meeting accessibility standards much easier. Instead of using the unintuitive measure of a contrast ratio, the system converts those same requirements to a simple difference in tone, HCT’s measure of lightness. Contrast is guaranteed simply by picking colors whose tone values are far enough apart—no complex calculations required. > For example, to meet [WCAG contrast requirements](https://www.w3.org/WAI/WCAG21/Understanding/contrast-minimum.html), smaller elements (less than ¼” or 40 dp) require a tone difference of 50 with their background, larger elements require a tone difference of 40. This principle works consistently for any pair of colors. Note that the minimum contrasts for small and large text (50 and 40) are different from the thresholds for WCAG 2.1 and for APCA; thresholds are algorithm-specific. -- GitHub Notification of comment by svgeesus Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/7357#issuecomment-1155539073 using your GitHub account -- Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config
Received on Tuesday, 14 June 2022 18:21:18 UTC