Yes vinyl siding can be painted and in the past it needed to be painted a lighter or similar shade. But Sherwin Williams now has
VinylSafe colors technology. Using their special color pallet you do not have to choose a similar or lighter than your old siding. Heat absorption has been the problem in the past. When you would paint the siding with a darker color the siding would warp and looks unsightly. Now Sherwin Williams seams to have come up with the solution with their new
technology.
We have yet to use this but we are ready if you are to change the look of your siding.
Please check your siding warranty, since painting it could possibly void any warranty it may have.
Final thought.
Even though Sherwin Williams says you can use a darker color I would still use a lighter or similar shade but that is up to you.