For example, while it is technically possible to have some shades of green background on which white and black letters both exceed the minimum contrast ratio by a bit practically all users will likely find either the black or the white harder to read than the other. The official contrast computation rules are not particularly perfect since they make some assumptions about green and/or hue that don't actually precisely track contrast recognition even in individuals without vision issues. Usually there will not be so try to think more inclusively and meet or exceed even the AAA minimums. While the official minimums for AA are an absolute minimum MSU requirement it is best to also remember that MSU has a broad MSU inclusion policy so if you find yourself tweaking something to just hit the AA minimum you probably ought to stop and ask yourself if there is any justification for hitting the bare minimum. However, it is important to make sure that fonts and images have a sufficient contrast or use other mechanisms to help visually impaired users understand the content. Region Chart Showing Non-contiguous Hatching AreasĬolor is an effective way to incorporate design aspects into your documents and websites.Installing the Colour Contrast Analyser (CCA).
Text, even within graphics should at least be true 16px at the size the image will be used but larger and/or bold could be better.
White backgrounds are fine, the user should have their device brightness adjusted properly for them, and do not waste time creating accessibility controls (such as for "night reading" or text size) because the user should be using the OS and browser tools for those.When text is over images always guarantee with a solid or limited transparency background that the contrast will be sufficient regardless of what image is in the background.Color and contrast are important but avoid red (or orange)/green and red/black foreground/background paring and, for greatest inclusion, approach or exceed the AAA 7:1 contrast ratio rather than trying to exactly hit the minimum AA requirements.Webmasters must take 100% responsibility for focus, hover, active, visited, and link indicators (outline, color/background changes, border, etc., while ensuring box/content size never changes) and their contrast when those can be controlled (such as by CSS in web pages).