Lenstip has been kind enough to test filters (with lab measurements):
UV filters test - Introduction - Lenstip.com Polarizing filters test - supplement - Introduction - Lenstip.com
With UV-filters there seem to be two schools of thought: 1) don't use them, they degrade IQ, 2) Use them for protection, the degrading effect is minuscule.
If you want to use one for protection, be sure to get a quality piece to keep IQ loss to a minimum, the cheapos may pretty bad in this respect (otoh, by the above test the basic Hoya HMC UV(C) would seem to be on par with the much more expensive B+W offerings). Actually, there should be no need for a UV filter as such since the sensor filter(s) should block it; UV-filters just happen to be the cheapest multicoated filters (probably because most glass tends to block UV) and so they are good for protection.
You probably don't want a CPL for protection as it cuts about two stops, also one might do just fine without a multicoated one assuming the filter is used only occasionally (for enchaning sky/clouds and to eliminate reflections (water, snow, shooting thorugh a window) then again the multicoated Marumi that did well in the above test seems to be reasonably priced so it might be worth getting that anyway, instead of, say the slightly cheaper uncoated Hoya.
As for color tint, this is probably best handled by manual white balance settings (or PP) when/if AWB makes a mess of it. AWB is usually does a fine job, though. The worst and most common enemy of it would seem to artifical light but even there the manual WB setting seems to do it (once you figure out the setting to use).