If you have just finished painting interior walls and the color has dried to a darker tone than you desired, you can lighten the paint with a faux finish. This will save you the time, effort and cost of having to strip the paint, re-prime and repaint the walls all over again. Lightening newly painted walls will require a bit of testing and patience, but in the end, you'll have the tone color you wanted.
Move any furniture away from the newly painted walls and put down drop cloths. Tape off any molding and decorative trim with painter's tape.
Mix TSP with warm water in a bucket. Clean the wall using a clean cloth and the solution. Do not drench the wall, just wipe it to remove any dust and allow to air dry before proceeding.
Mix faux glaze in a paint tray with the paint you used to paint the wall originally, according to the faux glaze mixing directions.
Dip a terry cloth or brush into the faux glaze/paint mixture and begin to paint over the wall. Use short, quick, light strokes so you don't blunt one area of the wall. The trick is to "color wash" the wall rather than actually paint it. The coat should be even and light, unlike painting, in which you apply one or two heavy coats.
Allow the faux glaze/paint mixture to dry for about eight hours or until the wall is no longer tacky to the touch.
Look over the lightened paint to see if it is as light as you wish. If not, clean the wall again and mix another faux glaze/paint mix, diluting the original paint color even more. Color wash the wall again.