Color and contrast in typography
Color and contrast are key components of universal usability. Text legibility is dependent on the reader’s ability to distinguish letterforms from the background field. Color differentiation depends mostly on brightness and saturation. Black text on a white background has the highest level of contrast since black has no brightness and white is all brightness. Hue is also a factor, with complementary colors, such as blue and yellow, producing the greatest contrast. Be sure your color choices do not make it hard for users to distinguish text from background. Also, never forget that almost 10 percent of male readers have some trouble distinguishing fine shades of red from shades of green (fig. 7.11).