Re: [csswg-drafts] [css-scrollbars-1] Clarify contrast expectations

Sorry for being late to this discussion.

The current wording after #3113 calls for “enough contrast” and links to Techniques G183 which calls for a contrast ratio of 3:1 or above, presumably in analogy with contrast recommendations for large text.

Now, I’d like to provide a data point. As a user/reader/developer, I find myself distracted by any contrasting spot of color that I see in my peripheral vision. A scrollbar thumb, 15px wide and having 3:1 contrast against the scrollbar track, and possibly more than that against the page background, certainly qualifies.

(I did a mockup in GIMP. A stroke width of 15px roughly corresponds to the letter I at 144pt font size. That is 8 times the definition of Large-scale text!)

As another data point, on my GTK+3/X11/GNU/Linux desktop, I am using a customized Clearlooks-Phenix theme. Specifically, I set the thumb color at `#e3e4e2`. With the default track color of `#d6d4d2`, it makes for a contrast ratio of 1.15. At this contrast ratio, the scrollbar is not distracting, and is clearly discernible for me when I’m looking straight at it.

Now, I cannot claim to be a real accessibility expert; after all, I’m only −5 diopters myopic and wear corrective lenses at all times. But I suggest that there may be a non-negligible category of users for whom web sites following the 3:1 scrollbar contrast recommendation will prove extremely annoying.

-- 
GitHub Notification of comment by yurikhan
Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/2968#issuecomment-436347945 using your GitHub account

Received on Tuesday, 6 November 2018 17:58:35 UTC