Paintbox Fudge temporary haircolor warning against using on eyebrows - blindness? for real?

I can tell you what the FDA web site says about the warning:

"Allergic reactions to dyes include itching, swelling of the face, and even difficulty breathing. Coal tar hair dye ingredients cause allergic reactions in some people. Synthetic organic chemicals, including hair dyes and other color additives, were originally manufactured from coal tar, but today manufacturers primarily use materials derived from petroleum. The use of the term "coal tar" continues because historically that language has been incorporated into the law and regulations.

The law does not require that coal tar hair dyes be approved by the FDA, as is required for other uses of color additives. In addition, the law does not allow the FDA to take action against coal tar hair dyes that are shown to be harmful, if the product is labeled with the prescribed caution statement indicating that the product may cause irritation in certain individuals, that a patch test for skin sensitivity should be done, and that the product must not be used for dyeing the eyelashes or eyebrows."

Besides the possiblity of getting some of the hair color in the eye, some people have sever allergic reactions to the dye.