When Crayola‘s senior designer Emerson Moser retired in 1990 – after 37 years of loyal services – he finally admitted he was color vision deficient… Moser went on to produce a record 1.4 billion crayons during his career! While any type of color vision deficiency (color blindness) could make crayon production difficult, complete color vision deficiency where someone can only see in shades of gray is extremely rare. About 99% of color vision deficiency is just the inability to distinguish between some couples of complementary colors. You can test your color vision on my website.
