We recommend using the Colour Contrast Analyzer, a free tool, to verify the your colors have sufficient contrast to be visible for those with vision problems. It is measured as a ratio comparing the difference in luminance between foreground (text) and background colors. It ranges from 1:1 (no contrast) to 21:1 (maximum contrast).

The ADA defines different ratios for graphic elements. We recommend ensuring your color contrast exceed 4.5:1 as this meets the requirements for all text regardless of its size. The ratio of 4.5 :1 is also appropriate for non-text displays (graphs and images).

You can download Colour Contrast Analyzer from the TGPi web site.

.The TGPi web site were you can download the color contrast analyzer


Notice, you can download either the Mac or PC version.

Once you run the CCA, you will see a window with a pane that allows you to select the foreground color, a second pane to select the background color, and a third that displays the results.

The color contrast analyzer window with the three panes highlighted


Last modified: Thursday, October 30, 2025, 11:09 AM