those little wire cover things.
 

So I just got a 2000 Mustang GT and it has the defualt black wire covers under the hood and i see a lot of people add colored ones to make it look better... I was wondering what those are actually called and were I can get them and mow many feet I would need to cover everything.

There called wire looms. And you can get them pretty much anywhere even a local auto parts store will have them. However be warned its the easiest path to the dark side of classy to tacky. So dont be ridiculous and put blue,red,etc... all over your engine it just makes it look like shit. My advice go spend money elsewhere.

dude... mega ditto's to that.

I shamfully nod my head to this. I made this mistake with my first Mustang. Stick with black.

well my black ones look like shit so where can you get new BLACK ones.