Have old brass fireplace doors. Would like them black or some other color. Can I paint these? If so do I need to take the glass out? And with what paint?
Yes you can paint them. You will need to use a heat resistant paint. Your options for paint will be limited at the Big Box Stores. I would look at either automotive engine paint at the local autoparts store or paint specifically for stoves from a wood/pellet stove dealer. My guess is that color choice will be limited. The glass need not be removed. You can mask it off with tape and remove the tape later. The results may be better if you remove the tape prior to the paint curing as the edges will be less likely to chip. You will get a better finish with the glass out but it may be difficult to remove. Some models hold the glass in with trim pieces held with screws. Other models crimp a metal lip to retain the glass. Recrimping the lip tight enough to get a good seal might be difficult to do at home.
Take your time in masking. Do it very carefully. It's the key to a good final product. I did it to mine and it's still perfect after many years. I primed the surface with a sprayed gray metal primer before applying the heat-resistant paint, as I recall, but read the paint can for instructions.