Develop Color Design Under User Conditions
Many factors affect the perception of color, and these effects are generally
not uniform across the spectrum. Apart from physiological differences among readers, external conditions such as lighting, screen brightness, and surrounding colors dramatically change the way in which color is perceived. Impressionist painters were masters at capturing these perceptual subtleties. A basic principle, therefore, is to design in an environment that is as close as possible to the one in which a text will be used. For darker viewing, light elements on a darker background are easier to read and less tiring; for brighter environments, the reverse is true. In any case, contrast is the most important factor for legibility.