blue residue in stove

Hello everyone, I have a quick question. Has anyone ever noticed a blue ash covering the inside of their stove? I just opened up my koker and noticed a light blue covering on all the interior surfaces. I am assuming it is just a by product of something burning off of the coal or maybe something in the basement air that got sucked in to through the combustion fan. I am using bagged blackshak rice coal, but this is the first time I ever experienced this. I doubt it will hurt anything other than making the inside of my stove look a little girly!!!

Boy 31 years of burning, hand fed and now a stoker the only blue I saw was the dancing ladies

That's a new one to me, too. Any chance you can get a picture of it?

Blue light in the room.
Or just too many Blue Lights. It was 9pm on Fri when he saw the blue haze