Mix TSP and laundry detergent in a bucket with 1 gallon of water. Scrub the bricks with this solution, using a natural bristle brush. Allow the bricks to dry before proceeding.
Mix 5 parts lime with 1 part salt and add water until the mixture is the consistency of cake batter to make an opaque whitewash, or until the mixture is the consistency of ink to make a translucent whitewash. Paint the whitewash wherever you want the bricks to look lighter. A light coat of whitewash will create the illusion of mineral or ash buildup.
Spray or paint a 10 percent bleach solution on the bricks as an alternative to whitewash where you want the bricks to look lighter. The bleach will remove some of the bricks’ pigment.
Paint the bricks thinly with a masonry primer, followed by matte latex paint for a more solid, dramatic light color. This will give the illusion of weathered, painted bricks.