One very easy, inexpensive way to play...

Dye-Na-Flow is a free flowing, transparent, textile paint. Dampen the fabric with either a brush or a spray bottle. For a blended effect, mix your fabric paints right on the fabric, applying one color over another while the paint is still wet.

Rainbow started it's life with a black and white fabric very much like this one. Dampened the black and white flowers and dropped paint until I liked the look.