Since the refurbishment at WL last year, the rooms are all painted a very light ivory color, so they are not dark at all. The beds now have white duvet covers instead of the dark spreads too. The lobby itself is darker because of the wood, but the rooms are not. I have no opinion on the pools, other than to say the clown at BW does not bother me in the least.
I like to stay at both BWI/BWV and WL. I stayed at BW in December and WL earlier this month, as a matter of fact. I have another stay at each booked for later this year as well. I stay at BW when I plan on focusing more on Epcot and DHS, and I stay at WL when I plan on focusing more on MK. So I would give a lot of consideration to where you will be spending most of your time. If you are planning to spend more time at MK than anywhere else, go with WL. If you are planning to spend your time more evenly between the parks, then the advantage of walking to two parks is a big one.
I haven't had any problems with the buses at either resort. WL sometimes shares with other resorts, and BW always shares with at least the S&D, so either way, you will be stopping at other resorts at some point in your travels.