Daniel Twogood writes:

>  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.


I found the following description of caramel and its manufacture in the 1997
Britannica CD-ROM Encyclopaedia.

George Kontos


Caramel

Candy substance obtained by boiling sugar to or beyond approximately 240 F
(115 C), at which point its mass takes on a slightly yellowish colour and
pleasantly burnt  smell.

Caramels vary in consistency between the short, or soft, and the long, or
more chewy types depending upon the proportions of ingredients. Corn syrup
added to the basic sugar constituent controls graining and contributes body.
Milk, essential to the traditional "carmel-candy" flavour, imparts a creamy,
collapsible consistency. The blended ingredients, including fats and
starches, are stirred continuously during cooking and then poured into
vessels or over cooling slabs in preparation for cutting and wrapping.

Caramels and toffee processing.

The manufacture of  caramel and  toffee resembles hard candy making except
that  milk and  fat are added. Sweetened, condensed, or evaporated milk is
usually employed. Fats may be either butter or vegetable oil, preferably
emulsified with milk or with milk and some of the syrup before being added to
the whole batch. Emulsifiers such as lecithin or glyceryl monostearate are
particularly valuable in continuous processes. The final moisture content of
toffee and particularly of caramels is higher than that of hard candy.
Because milk and fat are present, the texture is plastic at normal
 temperatures. The action of heat on the milk solids, in conjunction with the
sugar ingredients, imparts the typical flavour and colour to these candies.
This process is termed caramelization.

Because caramel is plastic at lower temperatures than hard candy, it may be
extruded. Machines eject the plastic caramel under pressure from a row of
orifices; the resulting "ropes" are then cut into lengths. Under continuous
manufacturing, all ingredients are metred in recipe quantities into a
container that gives an initial boil. Then the mixed syrup is pumped first
into a continuous cooker that reduces the moisture content to its final
level, and finally into a temporary holding vessel in which increased
caramelization occurs, permitting the flavour obtained by the batch process
to be matched. The cooked caramel is then cooled, extruded, and cut.