Each year I spray my stove pipes with a fresh coat of high heat black paint. As the pipes heat over time, the black turns to gray. At the hottest area near the stove, the paint eventually wiped away when I wiped the pipes with a damp cloth. I use a magnetic thermometer on the pipe to monitor the temp. Does anyone have any tips for keeping the pipes nice and black other than painting them more often? Thanks for the tip about using some ash with a damp cloth to clean the glass. The ash worked great.
Okay, on the serious note, during all my years of burning I've found that black stove pipe eventually turns greyish in color. All materials have their limitations. Steel stove pipe painted black is no exception. Some great suggestions may work, such as pen's suggestion of brushing on high heat paint. Or you might have to live with discolored pipe after you wear it in.