Blue Food Coloring offers a vivid color option with a wide variety of use applications. The Department of Transportation (DOT) requires the color to be used during drug testing and there are many municiple codes which call for its addition to recycled greywater. In the private sector, owners of swimming pools use the hue to enhance the appearance of the water. The color blue is generally associated with dependability and loyalty while evoking a perceived taste profile of tartness. Blue 1 is the certified color ingredient in the majority of blue food coloring products and provides a consistent standard deep shade of blue.