Purple Sweet Potato Sourdough (optional blueberries)

What color! Doesn't everyone want to eat purple bread lol! This is Cathy's regular sourdough loaf with a small but potent addition of purple sweet potato powder which adds moistness but no distinct flavor.  Guild the lily with the optional dried blueberries added in! Would make a unique and beautiful addition to a party sandwich/charcuterie board  (definitely a conversation starter for guests!).