Theoretical and experimental investigations of the color vision system in honeybees are reviewed. Grassmann's model and receptor models of color vision are discussed with respect to the problem of color difference. A recent analysis of the bee's color opponent coding system is presented in brief. Predictions for the spectral sensitivity of color opponent coding neurons derived directly from the color opponent coding (COC) model and predictions for the Bezold-Brücke color shift and the spectral discrimination function derived from the model via color difference formula are presented. The predictions are compared with electrophysiological data and with choice proportions of behavioral experiments, respectively.