There are a number of tools available on the internet which will test the colour contrast of web documents and computer generated images. A number of these are listed below, though none are endorsed.
Colour Contrast Analyser from Colours on the Web
Colour Contrast Analyser by Vision Australia
Colour Contrast Analyser, Version 2.2 from the Paciello Group
Luminosity Colour Contrast Ratio Analyser from Juicy Studio
Vischeck
If checking documents or images that will be printed out, please be aware that the colours displayed on screen will not match the colour that is printed. Therefore colour contrast on screen may be acceptable, but poor when printed. This is because of variations in how monitors display colour and printers print colour.
Colour ratio
The Web Content Accessibility Guidelines (WCAG 2.0) have been created to enable web developers to create accessible content. Part of these guidelines are related to creating good colour contrast and ensuring that foreground content stands out from background content.
Links to the WCAG 2.0 pages related to good contrast:
If you would like training, consultancy or in depth advice about creating accessible information; or feedback on existing documents, please contact RNIB's Services for businesses:
RNIB Commercial and Operations team
Phone: 01733 37 53 70
Email: businesslink@rnib.org.uk
For general advice or information about accessible information contact: accessibleinfo@rnib.org.uk