The Thermaltake C1000 Opaque Vivid Color Coolant Series. Made in Germany, the C1000 Opaque coolants are a non-transparent, virtually odorless, biodegradable, high performance PC liquid. Offering ideal protection for PC cooling systems using copper, nickel, brass or aluminum materials, the C1000 also supports anti-rust, anti-freezing and water scale prevention. Take control of colorizing any system from seven vivid colors: red, green, blue, orange, yellow, white, and purple to brighten up any build with Thermaltake. Yellow.