Concreation has a 31 year history of studying the influence of various portland cements and sands on the final color and appearance of concrete surfaces. The differences between TXI, Holcim and Lehigh gray portland cement range from a value of 7 to 4 and from dark bluish gray to pale warm gray. The sands have equal influence on the final color. The limestone in Bridgeport, Texas is dark and warm, the Parker county quarry is lighter and more amber. The result is you have no idea what your concrete will look like. You may end up with a building with rich warm colors and clashing pale bluish gray concrete paving.
Concreation is a tool for architects, designers and owners to create the distinct look and voice of concrete surfaces, not leave it to chance.