In order to compare the influences on the observers color discrimination with normal color vision under different viewing conditions, the lighting sources with different spectral power distributions and displays with different primary colors are selected, and the four color matching experiments are carried out based on the monitor and printed color samples. The 47 color matching functions (CMFs) of Stiles-Burch are used for a computational color matching simulation and 27 to 36 observers with normal color vision are organized to carry out the color matching experiment. The mean color difference from the mean, observer metamerism magnitude and variability are used to quantify different observers color discrimination. The results show that the spectral power distribution of the monitor primary colors and the light sources have much effect on the observers color perception for color matching simulation, especially in gray color center, but it is not suitable for the color matching experiment. It indicates that the observers color discrimination is not only determined by the observer color matching function difference (observer metamerism), but also the visual mechanism and ability of color discrimination etc.