Add one-half part hydrated lime, three parts fine masonry sand and one part Portland cement into a wheelbarrow. Mix dry ingredients completely. For larger jobs, you may want to rent a power mortar mixer rather than using the wheelbarrow.
Add water slowly, stirring constantly, until you get a think, pasty consistency. Do not add too much water, since the stucco will not hold its shape.
Add color pigmentation, if desired. The amount of pigment to add is dependent on how dark or light you want the color to be. Begin by mixing a small amount of pigment to the mixture, and add more as desired.
Remix the stucco mixture regularly as you work. This will help to keep the stucco from drying out.