Wash the tagged wall with a spray of water from a hose and a large scrub brush with dish soap to remove the dirt that may interfere with the new coat of paint. Wipe away the excess water with paper towels and wait 12 to 24 hours for the wall to dry completely.
Lay down a drop cloth under the wall to protect the surrounding area from drips or overspray from the new paint. Cover the wall with a thin, even coat of outdoor paint primer and wait eight hours for the first coat to dry before adding another. Wait 24 hours for the second coat of primer to dry. If you had a hard time matching the cover paint to the paint on the wall, you will need to prime and paint the entire wall to make it blend in.
Paint the wall or the area of the wall you primed with the colored outdoor paint in a thin, even coat. Wait at least eight hours for the first coat to dry before adding the next coat. Make sure no one leans against, or touches the wall for 24 hours while the paint dries completely.