Decide upon a color scheme for the deck. Visit a few paint stores in your area and select a number of color samples that would work well with your deck. Pick colors that complement your house color and the deck furniture. Keep in mind the natural colors in your yard as well as landscaping colors, such as bricks and wood.
Lay the paint samples on the deck. Remember color is affected by sunlight, especially in an outdoor environment. Lay the paint samples on areas around the deck. Also hold the samples up to the house siding and the deck furniture. Do this a few times to get a feel for how the sunlight affects the color. Select the color or colors that you think work best for your deck.
When you purchase paint for your deck, you also need to consider the sheen-level, the level of glossiness in the paint. Paint sheens range from flat, little or no gloss, to semi-gloss, which is very glossy. Don't be afraid to ask questions at the paint store.
Select a high quality oil-based paint. Oil-based paint offers better protection for a deck and stands up better under severe weather conditions and foot traffic.