Template:Ensure AA contrast ratio/doc

Usage
This template checks for compliance with WCAG G17, i.e. that a background–foreground colour combination has got a contrast ratio of more than 4.5:1. It takes two arguments, the  colour value, and the tracking category, , to place non-compliant transclusions in. A third parameter,, is optional; the template will by default calculate the contrast ratio against black and white, on the assumption that it is used in conjunction with.

Note: this is compliant with AAA for 18 point or 14 point bold text.