Today, people use sand that has been back-lit with gleam to create nice color pops that are otherwise impossible to make.
With the addition of goo farming and pigment, I was really excited to be able to make any color sand imaginable to come up with a lot of really dynamic lighting solutions. However since we can only paint Rock and Wood and their derivatives, that dream has died a little.
My suggestion is to allow painting sand to help open up the possibilities a bit and/or add a cloth block with a subtle, seamless, texture like sand has so we can craft our desired effects without working around an intense texture.