I don't think it would look bad. When painting it make sure you get some plastic primer, it will adhere better to the plastic than regular primer will. Oh, and also make sure you scuff up the grill to help with the adhesion of the paint. Just be careful when scuffing up the grill not to get carried away, because if you do it will show up through the paint. You can use a 3M scotch brite pad for the scuffing of the grill.