Which of the following is NOT a type of hair color?

Invisible color is not recognized as a type of hair color within the field of cosmetology. The other three options—permanent color, semi-permanent color, and temporary color—are all well-established categories for hair coloring processes that serve different purposes and offer varying degrees of longevity and chemical interaction with the hair.

Permanent color is designed to provide a long-lasting change to the hair color by chemically altering the natural pigment. Semi-permanent color offers a temporary alternative that lasts through several washes but does not penetrate the hair shaft as deeply as permanent color. Temporary color usually coats the hair without penetration and can be easily washed out after just one shampoo.

Invisible color, on the other hand, does not fit into any established category of hair color. It does not denote a specific application method or effect on the hair. Hence, it is not recognized as a legitimate option within the industry, making it the correct answer for which option is not a type of hair color.