Almost every product you buy off a shelf has food coloring in it. Why? To attract you. Green margarine wouldn't look very good so they dye it yellow. The problem with these artificial colors is sometimes they are made from bugs such as the cochineal bug (red5) but on top of that they are tested on animals. Your food doesn't even need coloring it doesn't add to the taste it just makes it look better, so is there an alternative? Yes, natural food coloring.

Homemade:
Red/pink= Beet, Cherry, Raspberry, or Pomegranate Juice.
Yellow= Tumeric
Purple= Acai, Blueberry, purple cabbage or Plum Juice (made from simmering ripe plum skins)
Green= Spinach or other herbs
Blue= Boiled red cabbage or blueberries
Brown= Coffee or Tea
Orange= Mix Red and Yellow ingredients
Black= Swiss Chard Juice

Pre-Made:
India Tree food coloring- not all vegan some contain bee wax ( look for the raw sugar and carnauba wax, which is made from the leaves of the palm plant.)
Natural Flavours liquid/powder food colorings- vegan, kosher, gluten free.

Sources:
http://www.yourdailyvegan.com/2011/10/warning-what-you-dont-know-about-food-colors/