Can you still use an iron skillet with the blue color of the baking blue off?

Yes. When the baking blue iron pot blue fell off, revealing the original color of the iron pot, but will not have an impact on the use of the iron pot. Baking blue is a steel surface treatment process, through high temperature heating to make the surface of the iron pot oxidation to form a layer of oxide (iron oxide), the color is blue or blue-black. This layer of oxidized layer can protect the iron pot from corrosion, but also can increase the service life of the iron pot.