Colour coding for Nitrous oxide cylinder is
(C) French blue IDENTIFICATION OF MEDICAL GAS CYLINDERSGasColor of cylinderPressure at 15degC when full British standard (Body/Shoulder)United StatesLbf/in2Bar1. Oxygen (O2)Black / WhiteGreen19871372. Nitrous oxide (N2O)French blueBlue638443. CyclopropaneOrangeOrange7354. Carbondioxide (CO2)GreyGrey725505. Helium (He)BrownBrown19871376. AirGreyYellow19871377. O^HeliumBlackGreen/Brown19871378. OJC02BlackGreen/Grey19871379. EntonoxBlueBlue/Green1987137
Black
Black with white shoulders
French blue
Gray
Miscellaneous