Prime the walls with a regular, untextured paint roller. Dry completely.
Apply the base coat in an even layer using a regular paint roller. Allow the paint to dry, then apply a second coat. Allow the paint to dry overnight.
Mix 1 part of your middle color paint and 4 parts glaze; the mixture will turn the paint slightly translucent, so it will blend with the base coat, giving it a natural look. Coat a heavy nap drywall texture paint roller with paint glaze, then do a practice roll on a piece of newsprint to remove the excess glaze.
Roll the middle color glaze over the base coat, switching directions frequently, to cover the entire wall. Some of the base coat should show through, but this layer should be heavier than a light smattering of dots. Allow the glaze to dry overnight.
Mix your top color paint, which will be the speckle, with glaze in the same 1 to 4 proportion. Using a stipple paint roller, practice applying the glaze on newsprint until the effect is a light speckling. Roll the glaze on the wall, changing directions as you roll, until the surface is speckled all over.