From the current state of the poll, opinions are split 50/50 between the current look and a more natural look. So I say keep the current aesthetic, but make it feel grittier and more lived-in.
One of my favorite things about Banjo was that, unlike every other kids game at the time (bright colours and clean textures), it had a ton of grit to it. There was crap on the walls and sewage pipes everywhere, mold, moss, cracks, scratches, dings, dust, rust, crust, toxic waste and industrial equipment, etc. They were densely-packed and felt lived-in. That was one of the reasons it was better than every other platformer I'd played. I'd like to see that kind of a world in Yooka-Laylee too.
The game is in very early development, and what we've seen so far has been created quickly to give people a basic idea of what the game will look. I bet the final product is going to look very different, and I'm sure the guys at Playtonic are going to factor in our thoughts on the visuals the more they develop the game.
I'm looking forward to seeing how the game shapes and changes over the next few years.