A study was carried out to determined how individuals with normal and defective color vision use 11 basic color terms to name samples from all areas of real color space. Thirty individuals with normal color vision used 11 basic color terms (red, orange, yellow, green, blue, purple, pink, brown, grey, white and black) individually or in combination to name samples from the Optical Society of America-Uniform Color Scales. Results indicate that individuals with color vision defects do not use all 11 basic color terms equally and those with a severe defect do not reliably use any of the 11 basic color terms.