Understanding Color Vision Deficiency
Color vision deficiency comes in several forms. Deuteranopia (reduced green sensitivity) and protanopia (reduced red sensitivity) are the most common, collectively affecting roughly 8% of men. For people with deuteranopia, red and green may appear as the same brownish-amber — making the near-universal convention of red-for-error and green-for-success entirely inaccessible. Tritanopia (reduced blue sensitivity) is rarer but also important to address in blue-heavy design systems. Understanding which types you are designing for determines which simulation tools and palette tests you need to run.
