Thank you Jerry. At the risk of offending my young friend, SEM makes a product called Color Coat which comes in aerosols and also can be custom matched to any color. It can be used to "enhance the color of carpet and velour", it is not intended to make drastic changes in color, only to brighten up existing colors, and should only be used on short napped fabric and carpet. I would worry about dye coming off too, but I think you would be safe with this. Even though I always refer to them as dyes, SEM products are not dyes, they are "permanent flexible coatings" that will not peel or crack if the substrate is properly prepared.
No one lives forever, the trick is creating something that will.