Don't be freaked out... Do you recall eating anything containing blue food coloring ?
Once we had a birthday cake with blue icing and the next day ~everybody~ was having blue #2!
Or it could be hopefully some thing in nature...
"Dr. Silas Villas-Bôas' research group has screened hundreds of New Zealand pigment-producing fungi, bacteria and algae, resulting in successful isolation of a variety of yellow, red, orange, pink and blue pigments. These have been tested for water solubility and heat, light and pH stability, and thus have great potential for use as food-grade pigments." http://www.cmi.ac.nz/applications.html