Personally, when it comes to cinnamons, they should be lighter. The dark markings should be closer to the color of cinnamon. Especially the top of the head... It's black pastels that should have very dark, shiny black markings.
Both can have a black back pattern but it's more common with cinnys. The black back pattern shows a more solid pattern along the spine, less spotting along the spine, and more blushing is apparent in that pattern.. It just looks nicer to me, and the majority of cinny lovers I believe.