According to wikipedia:
Blue Smarties were re-introduced in the UK in February 2008, using a natural blue dye derived from the cyanobacteria spirulina.[4]
Violet Smarties are dyed with cochineal, a derivative of the Cochineal insect which is listed in the ingredients as carminic acid. Its presence means that Smarties are neither kosher nor vegetarian.[5] [6]
So there you have it. Smarties are made from insects and bacteria.

