I have one bulk blend that is always my go to tobacco. Often I don't get to smoke the whole bowl and will save the rest for after work. I have really never looked in the bowl after dumping some ash, before I do a light. The past couple smokes after I dumped the ash I noticed on the top of the un smoked tobacco it seemed to have a very blue color to it. Nothing has tasted or smelled different or tasted funny. Has anyone an explanation for this?