<prompt> True about colour blindness: September 2005Autosomal dominant inheritanceTritanopia is the commonest disorderTrichromats are unable to appreciate blue colourDefect in 1 or more prime colours  <response>: Ans. D: Defect in 1 or more prime colours Colour blindness is inherited as recessive and X-linked characteristics. The prefixes Prot- Deuter-and Trit- stands for defects of Red, Green and Blue cone systems. So tritanopia Rarest has Defect of blue colour. Trichromats are normal individuals. 