Wall coverings

So I will have a bay that is 10'H X 12'W X 10'D that will house my impact screen that has top and side blackout curtains already.

Should I just paint the walls of the room or use some type of carpeting to cover them?

If I use paint does it need to be black or dark?

Thanks

Personal preference. If you have blackout curtains that will keep balls from hitting walls no reason for future protection on walls.