I owned a 1920's house with a stone basement. I bought the proper kind of stain, made specially for masonry, and got it tinted black. it looked great as a feature wall, and thinking that it was safe to do this on an inside wall (I had an extension in the basement) and after a year, it started to look dull and grey. After another year, it looked terrible. I personally would not recommend stain as an option, but going with a high quality paint, you'll probably get about 5 years of maintenance-free enjoyment out of that.