A light, fast, refined petroleum product especially effective on close-tolerance valves. What distinguishes this valve oil"aside from its distinctive blue coloring the anti-corrosion agent It contains for extra protection. Blue Juice Valve oil is a light, fast, refined petroleum product That's especially effective on close-tolerance musical instrument valves. What distinguishes Blue Juice Valve oil-aside from its distinctive blue coloring-is its anti-corrosion agent for extra protection of your music instrument valves.