If your favorite garden gnome lost his color, dress him up again with fresh paint. The perfect paint for the job depends on what the gnome is made of -- resins and plastic require a specialty paint. Seal the gnome afterward with a spray-on UV-protectant clear coat.
If the gnome has been outdoors for a while, it may need a bit of a cleanup before painting. Wipe it down with a sponge dipped in mildly soapy water. Use a gentle brush such as a toothbrush or nylon scrub brush to remove moss or other buildup; pick off any peeling paint. Rinse off the gnome, and allow it to dry completely before priming or painting.
Prime the entire gnome with a spray primer; if the gnome is made of resin or a plastic-like substance, use a primer designed for plastic instead, otherwise it won't adhere. Place the gnome on top of newspaper or a tarp. Then spray in even, overlapping bursts while holding the can 12 inches or so from the gnome's surface. Flip the gnome over and prime the other side once the primer is dry to the touch.
Painting the Gnome
Paint the gnome using acrylic or latex paints -- ideally paint designed for outdoor use, although a protectant sealer over the paint will help keep it in place looking its best, regardless. Start painting at the top, working in one color area at a time. Fill in the tiny details, such as the pupils of the eyes, last. Because the gnome has been primed, any acrylic or latex paint will stick to it, even if the gnome is made of resin.
Protecting the Painted Gnome
Once the gnome's paint is dry, apply a spray-on UV-protectant sealer, spraying it on as you would paint or primer. A clear sealant designed for outdoor use works on any painted gnome surface, or you could use a non-yellowing exterior latex concrete sealer if the gnome is made of concrete.