Educators have a responsibility to make their files accessible to users. If students–all students–cannot see or hear the materials teachers create, then the are “inaccessible.” One of the steps educators should take to make their files and pages accessible to those who have vision disabilities is to make sure files have sufficient color contrast. The best way to do this is to create dark text on light backgrounds.
Colour Contrast Analyzer is a piece of software that can be used to check the color contrast of files. Download the software (for Mac or PC), then launch it. You use the eyedropper tool to choose the foreground and background colors and the software determines if the color contrast is sufficient and displays easy to understand results.