Why are all my edges darker when using texture paint when using texture paint I can colour the whole object (in this case its a lightsaber) but when I go in to add detail with a black or any colour the edges become darker all over the object and I don't know why. I first thought it might have been the UV unwrap and when selecting another UV unwrap option like Cylinder Projection it doesn't happen but the texture doesn't go on correctly as in it goes through the other side or something else. I am wanting to do a very basic texture paint with just black in the gaps and I can't figure out how to fix it. If you have any ideas on how to fix it please can you let me know, I have played around with different UV unwrapping but that doesn't seem to take away the problems? Thanks
Since it goes away with a subsurf it is a problem with too little geometry - too few edge loops to get a good interpolation across the edge. 
You can 


Use manual loops along the discs
Use edge split modifier to not interpolate across the sharp edges
Use the Bevel Modifier (if it doesn't work, google how to use it, or
send me a screenshot of your settings)


EIDT: I just realized, the subsurf modifier you mentioned might also mess with your UVs, try toggling split UVs in the settings.