Den makeover in progress. Painted walls gray, refinishing hardwood floors, would like to paint stone fireplace
Here's a post that might help you - https://www.truevaluepaint.com/how-to-paint-a-stone-fireplace.aspx
Is the stone in bad shape? Once you paint it you will ruin its value. Have you tried to just do a deep cleaning. Stone looks good with grey walls and wood. Please think about it.
HI! I am getting ready to do the same thing! My stone is dark, with various colors of mortars used over the years and I want a fresh look!