It looked pretty standard fantasy fare to me. Trailers are not something I put much stock in terms of tone. So, if it's "drab" in a trailer I don't think that's reflective of the actual film.Bottom line, I just don't see the point of doing a humorless and drab swords-and-sorcery flick - and, despite a CG beastie here or there, this preview sure looks like that.
But, I'll also be reserving judgement until I see the actual film.