I wouldn't go as far as to say it is foolish. Its not a die for your herp, at least I don't think thats what it is. Color enhancers are used to try to get some captive reptiles to resemble their wild counterparts. I don't know how this spray is used, it looks as though you spray it on the food. If you spray it on the animal I definately have my reservations. For example, some amphibian hobbyist supplement with paprika and/or beet powder to try to perk up some of the red colors in some species. The idea is that there is a lack of caretenoids in our herp's captive diets which leads to some species not displaying their vibrant natural colors. I think it is apparent that our captive buddies are lacking something in their diets.
Like I said, if you spray your animal with it I wouldn't use it, thats almost like 'painting' your herp

. If its a spray for the food it might actually work to boost the natural color.