Soffits are the horizontal parts of the eaves on your house, located under and behind the fascia. Soffits often have vents installed in them where cool air can enter before traveling up inside the roof and passing through the vent at the peak. When you paint a soffit, be careful not to plug up or obstruct these vents.
Matching the Fascia
Most soffits are painted the same color as the fascia. Doing this creates a consistent color for the trim that separates the roof from the walls of the house. It is also easier to paint, because you don't need to carefully create a straight line between differently colored fascia and soffits. When the paint begins to peel on your house, the easiest way to repaint it is to scrape all of the trim, then prime it and paint it all at one time with a finish coat. Painting all the trim the same color makes this easy and creates an attractive finished effect.
If you are looking for an unusual effect, paint the soffits a different color than the fascia. Victorian houses with elaborate trim often have several different colors covering soffits, fascia and trim accents at their peaks and eaves. Be careful not to overdo it when trying this technique; too many contrasting colors can make a house look garish rather than beautiful. If you paint the soffits a different color than the fascia, use the brighter color for the fascia and the less dominant color for the soffit. This will help to bring out the more visible aspects of the fascia.
Not all trim is covered with colored paint. You can also protect the soffits by coating them with a clear finish, such as an exterior grade polyurethane, thus preserving the beauty of natural wood. This technique is most appropriate for more rustic house designs like shingled houses or log cabins. If you plan to leave your soffits natural, build them with wood that is free of knots and blemishes. These things are much more difficult to hide when you're not planning to paint the soffits.
Matching the Wall
Some houses are painted so that all the walls and the trim are the same color. While this makes for a somewhat bland facade, it does make the house much easier to paint because everything is the same color. If you paint your house in this style, paint the walls, soffits, fascia and other trim all at the same time, and you won't need to spend time carefully delineating the line between the walls and the soffits. You can also paint the soffits to match the walls and then paint the fascia a different color.