As far as UV filters for protection... that horse has already been beaten to a bloody pulp on these forums... then lit on fire... then beaten some more... and then some more, until it completely disintegrated and is now rising from the ashes like a demented phoenix...
As far as UV filters actually doing something photographically, I'm extremely skeptical. I've asked numerous people to show me an honest side-by-side comparison (one shot without a UV filter and the same shot with the UV filter) that demonstrates that they aren't totally worthless. Nobody has ever come through. I hear that their useful "up in the mountains"... I also hear that Bigfoot lives in every country on the planet and that aliens built the pyramids. You be the judge.
I'm not sure exactly what you mean when referring to filters that create "changes in color tone". If you mean something like a circular polarizer, then there's certainly a use for them in the appropriate situations. They can knock glare off of water and leaves and saturate colors. These benefits are available from a circular polarizer regardless of what lens you use. I won't venture into all of the situations in which they can be a hindrance more than a help, since that's outside the scope of this thread.
If you were referring to things like "warming filters", they aren't really all that useful. Most of those types of effect, which are primarily adjustments to color temperature, can be achieved digitally in post with negligible degradation of image quality (if you're shooting RAW).