The contrast ratio between a font and its background color is important to ensure readability. This contrast is calculated by comparing the luminosity of the background and foreground colors.
The ratio functions on a 1:21 scale, with 1 being the lowest readability and 21 being the highest. An example of this would be light grey text (#e6e6e6) on a white background (#ffffff) as seen here, in this example, the text has a contrast ratio of 1:24.
According to WCAG 2.1 the visual presentation of text and images of text should have a contrast ratio of at least 4.5:1. Large-scale text should have a ratio of a least 3:1.
Accessibility Assistant will by default have a contrast ratio of 4.5 and will assist you in assuring the contrast is large enough by suggesting colors from the color scheme used in the document.
Was this article helpful?
That’s Great!
Thank you for your feedback
Sorry! We couldn't be helpful
Thank you for your feedback
Feedback sent
We appreciate your effort and will try to fix the article