Help, help! Flat Responsive WordPress Forum Theme.

Hello guys, I want to install the Flat Responsive WordPress Forum Theme to my forum on my website over here. I am very pleased with the websites theme and dont want to change it. However my forum looks terrible and I want to install the Flat Responsive WordPress Forum Theme for the forum pages only.

Is this possible? Is there anyway to leave the rest of the site how it is with it’s current theme and make my newly developed forum have a entirely different theme? Or is it either one or the other for the whole site & forum?

Thanks a lot!
MrAlanC