is that metalic paint? if it is it will be a b1tch to match and to look right it will need to be blended in...
however if your just after tidying it up get the paint to match (try a test spot first and allow to dry to make sure the paint is a good match).
ideally you want an airbrush/small sprayer
i have in the past used an humbrol airbrush and it worked ok..
http://www.modelsforsale.com/catalog/product_info.php?cPath=8_89999112&products_id=309114
http://www.modelsforsale.com/catalog/product_info.php?products_id=295602
you will also need some very fine wet and dry paper 2000 -3000 grit
and a rubbing compound and a cutting compond and a good drying day..
have a read of this
http://www.automedia.com/Simple_Bumper_Scuff_Repair/ccr20020401bs/1
the thinner the coats of paint the better even if it takes 2 days to build up it will look a lot better than a rushed job..