Those of you who know me at all, know that I HATE additives, preservatives and artificial colours and flavours.
Anyone who has food allergies or intolerance (Which includes most people with Celiac) should be very careful about things like food colourings. (Store bought Red is made from crushed beetles for example)
I just found a site that gives you the how-to on making your own food colourings. This site has many other wonderful articles.
I hope you will check them out here: http://www.buzzle.com/articles/natural-food-coloring.html