I've had my hair dyed red for about two years now... Mind you, I mean bright red, and my hair is naturally quite light and course, so it holds dye well.
I didn't find it faded too badly, actually, I would have to re-dye every 6-8 weeks, which isn't ideal, but a good dye and an intensive conditioning regime kept my hair healthy.
I did mine at home, but I dye my hair a lot, so I couldn't afford a pro! But if you can, then I'm pretty sure it's a good idea.