Femtosecond lasers focused on metal surfaces can induce subwavelength periodic structures, which can make metal surfaces colorize. The hue and brightness of the structural colors vary with the incident angle of illumination and sample rotation angle, which indicates the structural color has directional property. In order to investigate the uniformity of femtosecond laser colorization on metal surfaces, based on the color system of International Commission on Illumination the color deviation is analyzed. The results show that the larger the processing area is, the worse the color uniformity is. With the specified experimental parameters, when the processing area of sample reaches to 64 mm2, the difference between edge color and center color is obvious to human eyes. Two colorized icons are made to demonstrate the effects of the directionality and uniformity of structural colorization on the practical application of femtosecond laser color marking.