To clearly discriminate different parts able not to be easily discriminated by the eyes and having the similar shape, so as to improve performance of a machine element product, by applying a colored part for discrimination to the similar part on a part of or the whole of a machine component.

A bearing 1 is composed of an inner race 2, an outer race 3, a cage 4, a rolling body 5, and a sheath 7. The rolling body 5 is a steel ball, and the whole front surface is taken as a colored part 6. The colored part is composed of a blackening layer, a phosphate coating layer, or a solid lubricant coating layer formed by sputtering of molybdenum disulfide. Accordingly, when the bearing 1 is shipped in the separated state and then temporarily assembled, whether the rolling body 5 is the regular part having compatibility can be discriminated at a glance, and an irregular different part or a similar part is prevented from being accidentally mixed in the bearing 1. Moreover, lubricity, rust resistance, and abrasion resistance of the rolling body 5 can be improved by the solid lubricant coating layer. The colored part 6 formed by the similar material and method may be applied on either the rolling body 5, the inner race 2, the outer race 3 or the cage 4 or on all of them.