Concrete "Coloring"

We are finally getting closer to "coloring" our outdoor concrete!  Instead of an acid stain we plan to use a safer and much less expensive method!  The use of iron sulfate and water. This product is sold at garden centers and is used as a soil amendment.  You mix it with water and apply.  Some friends have done a floor in their art studio and it looks great!!!  I am steeling Lisa'a idea and painting on the floor first, perhaps the a'ama crab (rock crab) that we see all the time on our cliffs!

I am off to town to locate some iron sulfate....