Itqualityassurance
- How to measure contrast?
- What is contrast in color?
- Why is color contrast important for accessibility?
- What is an acceptable contrast ratio?
How to measure contrast?
Contrast is calculated using "relative luminance", which is defined as: The relative brightness of any point in a colorspace, normalized to 0 for darkest black and 1 for lightest white. The relative luminance can be calculated from any colour code (like HEX or RGB).
What is contrast in color?
Color contrast is a term used in color theory that describes the difference between different color hues. Tonal contrast — a different type of contrast adjustment — describes the difference between the lightest and darkest tones in the image.
Why is color contrast important for accessibility?
Color contrast impacts the readability of your content on the web and in print. It is especially important for users who are low vision or for users who are colorblind. Good color contrast means all users can see your content no matter the device they're using or the lighting of their surroundings.
What is an acceptable contrast ratio?
Color Contrast Ratios Guidance
Whenever using color in images, ensure that the colors have a contrast ratio of at least 4.5:1. This ensures that the text is still readable to those who may have color blindness.
