The colour is an important factor in the creation of web content as it contributes to its appearance, usability and accessibility. However, some users with impaired vision, have difficulty perceiving colours.
It is important to ensure that colour is not the only visual means of delivering information, indicating an action, prompting a response or distinguishing a visual element. It advisable to supplement the information the colour transmit, with some other visual means, for instance a textual description, images, icons or other highlights and contrasts (W3C, n.d.).
Vischeck:
http://www.vischeck.com/
Vischeck is a way of showing you what things look like to someone who is color blind.
AWARE Color Laboratory:
http://colorlab.wickline.org/colorblind/colorlab/
Source: W3C, n.d.: Understanding Success Criterion 1.4.1: Use of Color. https://www.w3.org/WAI/WCAG21/Understanding/use-of-color.html [31.8.2022].
Find more:
Wikipedia: Color Blindness