- From: Myndex via GitHub <sysbot+gh@w3.org>
- Date: Thu, 16 Feb 2023 05:42:22 +0000
- To: public-css-archive@w3.org
## _Undeclared Colors Fail_ Under WCAG 2.x, it is a failure to specify a text color without also specifying a background color or vice versa: https://www.w3.org/TR/2016/NOTE-WCAG20-TECHS-20161007/F24 By definition, specifying a transparency without specifying the color that transparency exists _on top of_, is the same as failing to fully specify the color at all. This does not mean that a given element must have both a foreground and background color, it only means that at some point in the cascade an unambiguous foreground and unambiguous background color can be determined (or none). **What is required, _is only one_ of these cases:** - **No** colors are the default user agent. - **All** colors are the default user agent. ### As such, any compositing operations must be completed prior to calculating the colors involved in a pairwise contrast test. This is true under WCAG2, and I would expect it to remain true under WCAG3 as it would be a mistake for it not to be. **However it's easier said than done.** See my next post for the deeper dive. -- GitHub Notification of comment by Myndex Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/7358#issuecomment-1432554515 using your GitHub account -- Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config
Received on Thursday, 16 February 2023 05:42:24 UTC