Colors must provide significant contrast and should never be the only identifier.
- When it comes to distinguishing something like what link is selected, color is not enough. Use an underline, or a box or something more clear than just a color change. For example, you might have a green and red box that suggests on or off. The colors alone are not enough. We have to add text labels in addition, i.e. ON and OFF.
- High contrast between background color and text color. (no grey on grey, or otherwise hard to read color combos)
Additional Tools and Articles
- Color Safe - Color Safe is a tool to explore beautiful, accessible color palettes for your website based on Web Content Accessibility Guidelines (WCAG).
- Color Contrast Checker - A WebAIM article where you can test the contrast between colors and see if it meets either WCAG AA or AAA level of compliance.