The work aims to anodize TC4 titanium alloy under different electrolytes and different voltages to obtain color film, discuss the coloration of color film with different process parameters, and analyze the coloration of color film by the color development rule. Ti6A14V titanium alloy was oxidized and colored by NaOH electrolyte, H3PO3 electrolyte and Na2SiO3 salt solution. The microstructure, morphology, phase composition, film thickness and color change of the oxide film layer were analyzed by metallographic microscope, SEM, XRD, AFM and 3nh color difference meter. The color of the film (L*, a*, b*) measured by the 3nh color difference meter had a periodic variation with the voltage. Before the voltage parameter was about 120 V, the anodic oxidation film of the three electrolytes was composed of amorphous titanium oxide, with the same color development law. The oxide film layer was dense and uniform, but the growth rate was slightly different. Film color development was a combination of interference enhancing light color and interference complementary light color. Through the formula of interference optical path difference of titanium alloy oxide film, the theoretical calculation formula of film thickness was derived. The AFM test results were basically consistent with the theoretically calculated film thickness. As the voltage continued to rise, the electrolysis reaction was severe, the micro-arc discharge phenomenon was observed on the macroscopic surface, and the electrolysis process transitioned to the micro-arc oxidation stage. In the low-voltage anodization stage, the TC4 titanium alloy colored film layer is composed of dense and uniform amorphous titanium oxide. The growth mode of the film layer is uniform layer-like growth with voltage. The principle of color development is mainly the principle of thin film interference. The voltage parameters can control the film thickness to obtain the desired color. The film growth rate in the Na2SiO3 salt solution is from 1 nm/V to 1.7 nm/V.