(Mostly) Accurate sky and bricks from my palette:
There has been a lot of contention about the color of the sky with some saying it is more purple than blue, etc. As you can see from my palette, it is an interesting shade between purple and blue. An interview with Miyamoto backs this up as he said they went for a more purplish sky at the time. The bricks are also a lot darker than people realize. The palette BMF_final2 is pretty close to my own but not right for many games. I would upload my own palette, but I still want to fine-tune it to the smallest degree before uploading in case people send it around.
Here are some other comparisons that show how off emulator palettes can be because the NES doesn't output pure RGB: