Abstract THE color of the yolk of egg has received considerable attention for it is known to affect the desirability of the egg. A yolk that is either too highly colored or too pale is objectionable. Palmer (1915) (1919) reported that specific feeds affected the color of the egg yolk and that the color was due almost entirely to the pigment, xanthophyll. A brief review of the methods devised for the measurement of this color indicates that Ridgway’s (1912) color standards were used as a basis for grading in the earlier work. Later, color standards were designed especially for yolk color [Parker, Gossman and Lippincott (1925); Sharp and Powell (1930)]. A more usable standard of comparison was offered by Heiman and Carver (1936) with the introduction of their Yolk Color Roter, but workers still found it difficult to get good color matches. For that reason more objective measurements were sought. Titus, . . .