First you will need to strip down the room & fix any damage those little angels have done. You should fix up any holes before you paint (you have boys you know there will be holes!) this will give you a quick DYI fix. Once this is done, sanded & smooth it’s time to move onto the painting.
Here’s a guide to picking the right kind of paint. as for color…It’s really a personal choice. Any range of blue, yellow or green will match a bright action hero. A more subtle grey or lighter color will make the characters really stand out on the walls. Personally, I would go grey & do a skyline.
The graphic above has all the super hero Pantone colors so you won’t have to guess! You can thank this guy! He also has the evil villains colors listed on the site.