Making Color Sand For Sand Art

As an elementary teacher, I often took the whitest sand which I could buy. Then I mixed food coloring with sand in a baggie. After that I dried the sand on a metal tray in the oven at 225 degrees. Stir a couple of times to make sure it all completely dries.

Use plain table salt & colored sidewalk chalk. Pour the salt into a shallow container, "rub" the chalk over it, before you know it you have colored "sand". My Girl Scouts loved doing this sand art craft.

You take regular "play sand", put it in a plastic bag, add food coloring, shake to color.

Back when I was a kid, we did a similar project making colored salt. Using colored chalk, put a small amount on some paper and rub the salt with the side of the chalk. Continue rubbing the salt until it is the color you desire. Then we used the colored salt the same as you would use colored sand.
I know its not sand but I would imagine you could try this with sand and see what happens.