Abstract: A method for regulating color of a hard coating, including the following steps: providing an amorphous alloy layer; forming an amorphous metal oxide layer on a surface of the amorphous alloy layer to stack the amorphous metal oxide layer on the amorphous alloy layer, so that the amorphous metal oxide layer and the amorphous alloy layer together form the hard coating, wherein a band gap of the amorphous metal oxide layer is in a range from 2 eV to 5 eV, and the color of the hard coating is capable of varying within the visible light spectrum depending on thickness of the amorphous metal oxide layer; and controlling the thickness of the amorphous metal oxide layer in the formation of the amorphous metal oxide layer to obtain the amorphous metal oxide layer of a predetermined color. A hard coating and a method for preparing the same are also provided.