Daniel Twogood <[log in to unmask]> asked:

>If anyone knows the ingredients in caramel coloring, or caramel, I would
>like to know. I've suspected it for years. Sometimes patients react, and
>sometimes they don't.

That is because the FDA's Standard of Identity allows various ingredients
to be used as a base for caramel coloring. When there is a Standard of
Identity further ingredient information need not be given.

Excepts from Ener-G Food's "Detailed Ingredients Listing":

Caramel Color
  The problem with caramel color is it may or may not contain gluten
  depending on how it is manufactured.  In the U.S.A. caramel color must
  conform with the FDA standard of identity from 21CFR CH.1.  This statute
  says- The color additive caramel is the dark-brown liquid or solid material
  resulting from the carefully controlled heat treatment of the following
food-
  grade carbohydrates:
        Dextrose (corn sugar)
        Invert sugar
        Lactose (milk sugar)
        Malt syrup (usually from barley malt)
        Molasses (from cane)
        Starch Hydrolysates and fractions thereof (can include wheat)
        Sucrose (cane or beet)
  (Also acids, alkalis and salts are listed which may be employed to assist
  caramelization)