I guess I read the regulations on food coloring the same way that Irena does.
"Use and restrictions. Color additives may be used only for the intended uses stated in the regulations that pertain to them. The regulations also specify other restrictions for certain colors, such as the maximum permissible concentration in the finished product."
Must I match colors with intended use?
Yes. No matter whether a particular color is subject to certification or exempt from certification, U.S. law prohibits its use in cosmetics (or any other FDA-regulated product) unless it is approved specifically for the intended use [FD&C Act, sec. 721(a)(1)(A); 21 U.S.C. 379e(a)(1)(A)].
http://www.fda.gov/ForIndustry/ColorAdd ... 110032.htmAlso, there are some colors that have been approved for food, but have not been approved for cosmetics. Some things are safe to eat but could cause horrible irritation or staining on our skin.