Erratum

In the article "Color Defect and Color Theory" by C. H. Graham and Y. Hsia Science 127, 675 (28 March 1958)], the last 13 lines in column 3, page 679, appear in reverse order. The bottom line should be read first, the second line from the bottom should be read second, and finally, the 13th line from the bottom should be read last.