No 1 Brilliant blue colour dye came from coal tar or in our modern day it mostly comes from an oil base. No 2 Indigotine is a synthetic version of the plant based indigo used in textile colouring, or your jeans.
"Any chemical should be regarded as potentially harmful when ingested. Naturally occurring chemicals can be just as harmful as synthetic ones." https://www.scientificamerican.com/article/where-does-blue-food-dye/
