A full-color molecular pixel system is realized for the first time using simple mixtures composed of RGB-emitting excited-state intramolecular proton transfer (ESIPT) dyes, each of which has delicately tailored Stokes shift and independent emission capability completely free from energy transfer crosstalk between them. It is demonstrated that the whole range of emission colors enclosed within the RGB color triangle on the CIE 1931 diagram is predictable and conveniently reproducible from the RGB molecular pixels not only in the solution but also in the polymer film. It must be noted that mixing ratios to reproduce the desired color coordinates can be precisely calculated on the basis of additive color theory according to their molecular pixel behavior.