This is my experience, having had two girlfriends who dyed their hair red (and required my assistance with it).
The red color you're looking at will require you to bleach your hair first, and then it will require very frequent redye efforts to keep it from looking faded (about every 10 days), because red fades very quickly with light hair. You could dye it red without bleaching, but because you have dark hair already, it's going to be a pretty dark red.
If you're down for that, go for it, but it's a lot of work.
Go for it! Worst case scenario, it's just hair. You can always dye it different or cut it off or grow it out! I think it would look good! But you might want to get it done professionaly, I've heard it's really hard to get the right shade and not make it look splotchy if you have dark hair to begin with!