WebAIM - Web Accessibility In Mind

E-mail List Archives

Re: 1.4.1 use of color for state indicator

for

From: Jonathan Avila
Date: Mar 9, 2020 6:49AM

Hi Glenn, yes -- you'd want to take the contrast ratio before converting to grayscale as the calculation treats hues differently to help people with color perception challenges -- but applying a simple grayscale test would help people understand if it's really the hue or the luminance that makes the difference. For example, if you grayscale something and it says find the red text then it's obviously an issue. If you grayscale something and then you say which of your buttons is selected -- then you'd say -- the color (hue) doesn't make difference (e.g. whether it's purple or blue didn't matter) -- I'm really looking at lightness making a difference. As I understand it luminance and lightness are not the same thing -- but lightness is a easier to understand concept for me and most people. So if you then say it's lightness that makes a difference based on my grayscale tests -- then I go back to color and check the contrast ratio between the two items. So if the selected state only
relied on color difference -- does that selected state have >= 3:1 (I should have said >= in my prior email)?

Jon