How are they going to match the original color of the stone mortar?
This is going to vary from state to state and availability of materials. Mixing cements with different sand colors allows for a natural color to work with. Using dyes in the sand can help with finding the right color. I would ask for a few small samples if you’re going to be doing a larger size job. If it’s a smaller job, then ask about the different formulas they use to achieve different colors. If they look at you a little strange, then go see some of there work before you commit to them doing the job. I’ve seen some real bad colors that stand out like a sore thumb.
