A Validation of the Color-Preference Index

Four fluorescent lamps of daylight chromaticity, and with varying Color-Preference Index (CPI), illuminated an array of fruit, vegetables, breads and meat. The lamps were rated in order of preference for the coloration of this array by 267 observers. Excellent correlation of observer preference with CPI, as well as with the prime-color content of the spectral power distributions of the lamps, served to validate the CPI and Judd's assignment of preferred chromaticities of identifiable objects.