Since spidey won't be wearing the symbiote by then,and since Venom will be dead,spidey will have his red and blue suit.For the background,it could be at night.
I agree with GoldGoblin...we've seen Spidey swing during the day in both movies...seeing Spider-Man make his last swing in nighttime will be good...and people should stop saying 'At the end of S-M 3, they should show Venom ontop of a roof watching him from afar'...