Purple Rain starts out as an innocent-looking dark green powder, but when it comes in contact with any moisture, watch out.This stuff keeps coming out with a seemingly endless supply of dark purple stain.Imagine a sprinkle of it in a strategic spot in the bathroom, the doormat where people wipe their wet shoes, the swimming pool area, the drinking fountain, etc.Caution: this will stain most anything - use only with extreme caution and discretion.