Update to Color Contrast Tester

Example of test output of color contrast tester.

September 4, 2013

Topics: Accessibility, Web Development.

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So, I originally wrote my color contrast evaluator in September of 2008. Now, 5 years later, there are some key differences that merit an update.

Visit the Color Contrast Tester

In 2008, support for rgba color was virtually nonexistent on the web. Accounting for transparency was only something you needed to do with images. Mobile devices were something to consider, but it wasn’t that big of a deal – if a tool wasn’t mobile friendly, that was really the norm.

WCAG 2 was released — but WCAG 1 was still a major document in web accessibility, and many organizations still needed to test against those standards. (Despite the fact that WCAG 1 didn’t actually incorporate actual color contrast algorithms into their guidelines document.)

But all that has changed. I removed the WCAG 1 color contrast tests from the tool quite a while ago, but today I’ve made a couple other updates, including implementing some very simple responsiveness for this very simple page and incorporating testing of foreground colors with alpha transparency.

It can be tricky to figure out what color is actually being perceived if you have brown text on a grey background with alpha transparency at .8 — what *is* that color, exactly? This tool will now calculate that for you, and show you what perceived hexadecimal you’re actually getting.