Artificial food dyes are in an incredible amount of products that most people consume daily without a second thought. They are put into processed foods to make them look more appealing and no other reason. You'll see them listed as Blue 1, Blue 2, Green 3, Red 40, Red 3, Yellow 5, Yellow 6, etc. in the ingredients list. Several artificial colors have been banned over the years, which should be a wake up call.
So what is the harm? A lot of studies blame artificial food dyes for behavior issues in children, such as ADD/ADHD. If you have a child with a lot of behavioral problems, you may find the Feingold Diet of interest. I have read some on it, and it is certainly interesting (you are what you eat!). Some studies have also linked artificial food dyes to cancer. It isn't worth the risk for absolutely no reward!
Natural food colorings are being used more and more to give food the look we are used to without adding anything artificial to our diets. Look for ingredients such as annatto extract, beta-carotene, beet powder, paprika, saffron, turmeric, etc. And if you stick to unprocessed, whole foods you'll never have to worry!
Update! I just saw this posted to facebook - very informative!!!