Objective To analyze the composition of the oxidation color defects on the surface of cold rolled steel strip, and study the causes for the formation of oxidation color, then find the way to reduce oxidation color. Methods By simulating the annealing experiment in laboratory, we studied the influence of different materials at different tapping temperature on the oxidation color on the surface of cold rolled steel strip. By using Photoelectron Spectroscopy and field emission scanning electron microscopy, we analyzed the microstructure and elementary composition of the oxidation color produced in different ways. By using X-ray diffractometer, we conducted phase analysis for oxidation color. Results The results showed that the tapping temperature was the main factor for producing yellow oxidation color after strip annealing. The yellow oxide produced in the simulated annealing experiment was the same with that in the production field. The yellow oxide film was composed of four elements: O, Mn, Fe, C. The main compositions were iron and manganese oxides. The film was thin, and the thickness was about 50 nm. There was obvious enrichment of manganese element on some local surface. Conclusion The oxide formed oxidation color on the surface of cold rolled strip. In the process of annealing, manganese element enriched in sensitive position. When the tapping temperature was high, the Mn element was oxidized with priority and formed the oxidation color defect which had different color from that of the normal board. The corrosion resistance of oxidation color was lower than that of the normal board. Decreasing the tapping temperature could effectively reduce the formation of oxidation color.