This section is from the book "The Steward's Handbook And Guide To Party Catering", by Jessup Whitehead. Also available from Amazon: Larousse Gastronomique.
The brightest coloring for confectionery. The red shades from pink to purple are perfectly harmless, and if they were not the quantity required to color is so extremely small that no injury could ensue. The greens and yellows in aniline colors are all more or less poisonous and cannot be admitted to the pastry or confectionery room. Aniline is one of the many products of petroleum. Some years ago, when petroleurn and the substances obtained from it were new and but little understood, a French chemist undertook to ascertain the effects of aniline upon the human system by taking doses of it himself, increasing the quantity daily, and came to these conclusions, viz.: Aniline, pure, lias no effect, either good or bad. The chemicals used to make aniline red are perfectly harmless. The chemicals used to make aniline green, blue and yellow, are arsenic and other injurious substances. Consequently the reds may be safely used, but not any other colors. The quantity needed is scarcely more than five cents' worth for six months; the dip of a cork will color a gallon; buy dry aniline and dissolve in warm water.