If the walls are in poor shape prepare them for painting; apply the base coat and let dry. If desired, follow the parchment instructions to start this project, or simply begin with the existing color. Start with lighter undertones because adding color is easier than taking it away.
Tonality is the color or shade of a color; quality of a color.
Art-supply stores carry watercolor pencils. Roll them in your fingertips to make a sharp point when marking.
Mix one part of each top coat color with one part water and one part glaze in separate containers. Use a tape measure, watercolor pencil and a level to carefully mark the stripes. Straight lines are critical.
Put a small piece of tape on the stripes you won't be painting to keep it all straight. Put tape along the outside of the pencil lines of the stripes to be painted (make sure it's straight), and seal it with your fingers or a dry cloth so paint doesn't seep underneath.
Use the same colors for the stripes as were used for the initial parchment finish (the second layer will turn out a lot darker). Apply a few swipes of each paint mixture, and then spread it around with a damp cheesecloth in rounded, ameba-shaped movements. Then dab repeatedly to blend any lines. Once a stripe is done, pull the tape off right away so any excess paint under the tape can be wiped off with a rag.
When the finish is completely dry, remove the watercolor pencil with a damp cloth. This looks great as is, but you could dress it up with pinstripes or stencils.