In the color coding system, what color is designated for the top of recovery cylinders, with the bottom being gray?

Recovery cylinders are color coded with grey bottom and yellow top. The gray color at the bottom serves as a visual indicator that the cylinder is specifically designated for storing recovered refrigerants, distinguishing it from other cylinders used for different purposes. The yellow color at the top acts as a visual reminder to ensure that necessary precautions are taken to prevent accidents or mishandling.