The improvement of luminous efficiency is one of the most important issues in making a plasma display into a large flat panel device. Accordingly, a new combination of a four-component gas, He-Ne-Xe-Ar, is proposed in order to achieve a high luminous efficiency in color plasma display panels (PDP). The densities of 32 species and electron temperature were calculated using a zero-dimensional simulation. The results were then compared with measurements of brightness and luminous efficiency to identify the optimum mixing condition of He(7): Ne(3)-Xe(4%)-Ar gas for a color PDP. The reaction mechanism was computationally analyzed to comprehend the discharge mechanism in He-Ne-Xe-Ar as well as in He-Ne-Xe. By simulation, the maximum peak point of the Xe*(S-1(4)) state was obtained between a 0.1% and 0.5% Ar mixing ratio and the maximum luminous efficiency was measured with a 0.3% Ar mixing ratio in the PDP. As a result, the luminous efficiency was considerably, improved (about 20%) with a 0.3% Ar addition, compared with the conventional He-Ne-4% Xe mixing gas.