A fluorescent gas-discharge color display panel, in which a fluorescent material is excited by a gas-discharge therein, contains a three-component gas mixture of neon, argon and xenon as the discharge gas. Typically, the argon gas component is in the range of from approximately 5 percent to approximately 80 percent, and that of the xenon gas from a minimum sufficient to maintain the Penning effect up to approximately 10 percent. The argon gas component contributes to the gas mixture producing a pure and high peak of green light spectrum and reduces the orange light spectrum emitted directly by the neon gas discharges. Other characteristics, such as operating voltages, brightness, luminous efficacy, and the panel operating life, are satisfactorily maintained. The improved color purity is advantageous for both single and multiple color display by the excited fluorescent material or materials.