"79 3.5 LES COLORANTS ALIMENTAIRES La ... - UTC
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Avant 1850, les colorants alimentaires étaient d'origine naturelle (safran, cochenille .... Les chlorophylles sont les pigments verts des plantes. ..... Laques : le colorant est précipité sur un support adsorbant lui apportant une bonne stabilité à la lumière et à la chaleur."

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Note added at 14 mins (2014-04-17 20:59:42 GMT)
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"Dyes and lakes

Color additives are available for use in food as either "dyes" or lake pigments (commonly known as "lakes").

Dyes dissolve in water, but are not soluble in oil. Dyes are manufactured as powders, granules, liquids or other special purpose forms. They can be used in beverages, dry mixes, baked goods, confections, dairy products, pet foods, and a variety of other products. Dyes also have side effects which lakes do not, including the fact that large amounts of dyes ingested can color stools.

Lakes are made by combining dyes with salts to make insoluble compounds. Lakes tint by dispersion. Lakes are not oil soluble, but are oil dispersible. Lakes are more stable than dyes and are ideal for coloring products containing fats and oils or items lacking sufficient moisture to dissolve dyes. Typical uses include coated tablets, cake and doughnut mixes, hard candies and chewing gums, lipsticks, soaps, shampoos, talc, etc."
http://en.wikipedia.org/wiki/Food_coloring#Dyes_and_lakes