Color Contrast Between Text and Background Color
Provide sufficient color contrast between foreground and background, text and background color.
The contrast ratio between text and background, using regular body text, should be at least 4.5:1.
Large-scale text (24 pixels or 18 pixels bolded) should have a contrast ratio of at least 3:1.
Test your contrast level using this color contrast checker for WCAG AA compliance https://webaim.org/resources/contrastchecker/
There should be a contrast ratio of at least 4.5.1 between link text and background color. This applies to regular body text (or 3:1 for large text) .
There must be a 3.1 contrast ratio between link text and surrounding text.
Use this link contrast checker to test color contrasts for links https://webaim.org/resources/linkcontrastchecker/
When designing for color blindness, make sure that colors are not your only method of conveying important information.
Use this filter to test web pages for color blindness https://www.toptal.com/designers/colorfilter/
If the purpose of posting the content is to communicate something about the colors in that image or web page, then it is important to provide some other way of understanding the information.
Challenges | Solutions |
Reds and greens are often indistinguishable | This is not normally a problem except in cases where the colors convey important information. Under these circumstances you will need to either change the content or graphic or provide an additional means of obtaining the same information. For example, provide an explanation in the text itself. |
Don’t rely on color to convey critical information such as alerts and error messages. See more info about this under the Alert/Error Messaging section.