Color blindness is characterized by the inability to distinguish between certain colors, most usually green and red, and is more common in males than females. Color blindness is also a genetic, inherited condition so is more likely if there are color blind adults in your family. Although some toddlers know their colors, most do not. Even toddlers who have memorized their A,B,C's and 1,2,3's may not have mastered the different skill of categorizing by color. So, even if your toddler is not yet correctly identifying colors, that does not indicate color blindness. If your child recognizes some colors but only struggles to identify the difference between green and red, there is a test that an optometrist can perform on children as young as three. In this test, the child is asked to pick out shapes composed of red dots in a field of green dots or vice versa. The good news is that with minor modifications, a color blilnd child should have no real difficulty in school or in life.