I just picked up a 2018 Stumpjumper Expert. The bike is awesome and even with the cold weather here cannot wait to hit the trails.
I have the black frame color with the red accents, and I noticed on the frame that it is not a smooth color, almost looks like it is splotchy in places. It made me want to wipe at it when I first went to get the bike but it was not something that could wipe off. Is that something common with Carbon frames?
As well, I noticed that along with the manual came two sheets with stickers on them, one sheet had SPECIALIZED in black and another in White and both sheets had a bunch of different shape stickers, just shapes, no words no colors. I assume they are for spots on the bike, but I am not sure.
Can you add a photos? Some black frames are just clear coated and not painted. In that case you'll be able to see the fiber and many look as you describe.