Color Contrast Checker by WebAIM
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https://webaim.org/resources/contrastchecker/
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Accessibility Standards
Color Contrast Checkers
Color Blindness Filter
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Use this filter to test web pages for color blindness
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Accessible PDFs - Adobe Acrobat Pro and Microsoft Word
Step by step guide on how to create accessible PDF documents
How to make your Microsoft Word document accessible by Microsoft:
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Accessibility Testing Tools
WAVE by WebAim http://wave.webaim.org/SortSite by Powermapper https://www.powermapper.com/products/sortsite/checks/accessibility-checks/