Those are available from Phx called salt river rock.

This concrete is so perfect! It is a sand wash finish? What finish is the darker band on the steps?

Yes it is a sand wash finish. The steps appear to be a different color, but are a different texture, separate pour. Broom finish on the steps and borders.

Awesome, thanks so much. We have our concrete pour for our pool and patio next week and I don't believe they do much of the topcoat/sand wash finish, so kind of nervous to try it.