Metal surfaces can look brand new with a touch of new paint. Don’t think of painting anything metal until you properly prepare the surface, however, or your creative streak will only make a mess. Paint will not stay on galvanized steel, tin or aluminum that is not properly cleaned and prepared.
Clean the surface of new metal with mineral spirits which is available at any hardware, paint or department store. This will remove all traces of oil and grease left on by the manufacturing process. Galvanized steel -- such as that used in gutters -- has to weather about six months before it's safe to paint, otherwise the paint will come off very quickly.
Prime the surface with a primer made specifically for metals. You can find these at most paint and hardware stores and all businesses that cater to the industrial market. Now your metal surface is ready for painting. Be sure to use paint that is specifically formulated for metal.