No need to worry. Blue discoloration on mushrooms or mycelium is bruising caused by psilocybin, it's actually a sign of potency.
Quick way to tell the difference between bruising and contamination: gently press a cotton swab against the blue spot. If the colour doesn't transfer to the swab, it's bruising. If it does, it could be mold.
Blue = good sign. Your kit is doing its thing.