The number of colours of Grimas Fluorescent Water Make-up is limited because the other colorants currently available on the market that fluoresce under black light do not comply with Grimas' requirements for use near the eyes and mucous membranes. Grimas believes that such a requirement is obvious for cosmetics, particular if it is for make-up that is also going to be used on children.
This is in contrast with many other brands of products currently on the market that fluoresce under black light. These do often state in small letters on the back of the packaging that the product may not be used near the eyes or mucous membranes, or that the product must not remain on the skin for too long. Some brands stretch it even further by simply stating on the packaging that the product is not a cosmetic, but for example a paint for special effects.