Great tool for checking color contrast for both text and images of text.See the tool
DescriptionAnalyze a web page or portion of a web page for conformance with WCAG 2.0 Color Contrast requirements. The Color Contrast Analyzer chrome extension is great for checking color contrast for both text and images of text. It offers the possibility to scan for two levels (AA and AAA) of ARIA requirements. The extension applies a mask and highlights only the parts of the UI which fulfill the color contrast.
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A free online ADA and WCAG compliance checker.
Jumpstart Your Web Accessibility Efforts Directly in Google Chrome
Check compliance with WCAG 2.0 minimum contrast