What color identifies an AN steel flared-tube fitting?

AN steel flared-tube fittings are identified by a black color. This color coding is an industry standard used to provide quick identification of the material and intended application of the fitting. Specifically, black indicates a steel fitting designed for use with fluid systems in aircraft, which is essential for safety and compatibility. Understanding the color coding is crucial for technicians and maintenance personnel, as it helps to prevent the installation of incorrect fittings that could lead to system failures or safety hazards. The other color options represent different types of fittings or materials, so recognizing the distinct identification of black for AN steel fittings aids in maintaining proper maintenance protocols and ensuring the integrity of aircraft systems.