This powder colorant works on grout and cement and can be used for indoor or outdoor projects.
Before adding water to your grout or cement, dissolve 1 teaspoon of colorant in the water for each 1/2 pound of grout or cement you plan to use - then blend into your grout or cement. There are 24 teaspoons of colorant in each jar, which is enough to color about 24 square feet of mosaic grout. Colorant comes in a resealable bottle with directions printed directly on it.
WARNING: This product can expose you to chemicals including Titanium Dioxide, which is known by the state of California to cause cancer.