Using a color chart. Using a standard color chart with colors easily distinguishable they are pointed to and you are asked to identify the colors. This test is done to identify color blindness which is a hereditary condition.
Color chart. You will be presented with a booklet, page by page, with dots of different colors along the axis of confusion of the common color vision defects. The color deficient will confuse them and not see anything or make errors. Ideally this will be done under a specific color corrected light (a macbeth light) but that is not readily available. The test is generally reliable even with normal illuminati.