A model with the algorithm of piecewise linear regression and progressive addition is presented for producing colors having desired CIE chromaticity coordinates and luminances on general TVGA monitors without digital graphics systems. This method takes account of the interrelations among the R, G, and B phosphors based on the white-balance adjustment and calibration of the color monitor. On obtaining the tristimulus values of the sample color to be simulated, the frame buffer of the monitor is directly programmed and the digital input values to it are solved and then further corrected by iteration such that a vivid color is displayed on the CRT monitor.