- From: Wolfr via GitHub <sysbot+gh@w3.org>
- Date: Tue, 08 Jan 2019 09:24:21 +0000
- To: public-css-archive@w3.org
You are right, they are separate concepts. Conflating them would lead to confusion. Thanks for the clear explanation. On Tue, Jan 8, 2019 at 4:40 AM Alice <notifications@github.com> wrote: > To recap, I think there are several distinct concepts of contrast > preference: > > - *True high contrast*, along the lines of the Windows High Contrast > Mode. This is often a light-on-dark colour scheme with white or yellow > text, black background, reduced detail, few gradations of colour etc. This > is intended for users with unusual vision impairments, who may also use > other accommodations such as screen magnification to be able to access > content. > - Despite typically being light-on-dark, this is quite different > from a "night mode" theme. > - This is often an operating system setting which affects how text, > borders and images are displayed. In this case, developers may wish to make > adjustments to ensure that these modifications don't create other problems. > This is the "forced" case, I think. > - However, certain apps also provide high contrast themes > <https://blog.jetbrains.com/idea/2018/10/intellij-idea-2018-3-eap-high-contrast-theme-and-more-accessibility-improvements/>, > and it would be good to be able to allow users to opt in to these themes on > all sites which support a common theming mechanism, such as a media query. > - *Enhanced contrast*, along the lines of OS X's setting and Gmail's > current high contrast theme, which retain much of the "standard" palette > and level of detail but enhance borders and increase text contrast to > around the WCAG AAA level or better. The WCAG AAA level is intended for > users with moderate vision impairments with a visual acuity of 20/80-20/40. > - *Acceptable contrast*, which is denoted by WCAG AA > <https://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-contrast.html> > level. This is intended to be a standard contrast level perceivable by > people with 20/40 vision or better - considered "minimal vision impairment" > and comprising around 10% of the population of a typical wealthy country. > - There is also a small subset users who prefer *reduced contrast* for > various health reasons. > > These seem to map nicely onto the levels in #2943 (comment) > <https://github.com/w3c/csswg-drafts/issues/2943#issuecomment-437613516> > - although we seem to have lost the concept of "forced" from #443 > <https://github.com/w3c/csswg-drafts/issues/443> > > I don't know that we'd want to conflate "high contrast" and "enhanced > contrast", since they really look quite different and target different > audiences. Perhaps they'd need to be separate boolean queries? > > — > You are receiving this because you were mentioned. > Reply to this email directly, view it on GitHub > <https://github.com/w3c/csswg-drafts/issues/2943#issuecomment-452164677>, > or mute the thread > <https://github.com/notifications/unsubscribe-auth/AAAxkh92ypKO5VuvTeqMSQ8btEWM4yWiks5vBBMvgaJpZM4VZRI8> > . > -- GitHub Notification of comment by Wolfr Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/2943#issuecomment-452230014 using your GitHub account
Received on Tuesday, 8 January 2019 09:24:22 UTC