How dark is the wood? I saw someone commenting on the "oak" version of this product that it is actually as light as "birch" in real life and not what one would expect oak to be. Here it says "walnut" which is usually very dark but colors on the pictures are a bit confusing. I am looking for something closer to traditional "oak" color (actually exactly like the 3rd close-up picture of this "walnut" version). Which product would be better? Thank you.