Color Vision Deficiency

A condition in which a person has difficulty distinguishing between certain colors, most commonly red and green (deuteranopia/protanopia), but also blue and yellow (tritanopia) or all colors (achromatopsia). Color vision deficiency affects approximately 8% of males and 0.5% of females of Northern European descent. For digital accessibility, CVD means that information should never be conveyed through color alone—patterns, labels, and other non-color indicators must supplement color coding. Design tools and guidelines exist to help test and ensure content is perceivable by people with various types of color vision deficiency.