Just what "colour" do you prefer? (I kinda like blue, myself)
Seriously, a pre that actually sounds quite good is the Aphex 107. You can usually find them on ebay for around $100. It was one of my first pre's and I still can't bring myself to part with it.
It doesn't add alot of colour, but it does seem to add some warmth.
Then again...if you want something really "colourful" you could always get a BlueTube. (Hey! They're blue! I like blue...)
For $0, you'll be hard pressed to find anything (you can get some colourful free plugins if you are recording on your computer, though).
Any of the cheap "tube" pres (presonus blue tube, art tube mp, behringer pro-something-or-other) will add some flavor, but they are hit-or-miss and may add more "ugly" than "pretty." Alot of people like the Studio Projects VTB-1. I own one and use it quite a bit for vocals. If you can try them out in the store with your own microphone, that will give you the best idea of what will work for you. As for a real tube preamp that will give a distinct sound, you are looking at $$$$ and that is far beyond my realm of knowledge. Good luck.