Ace the NOVA Clinical Anesthesia Exam 2026 – Your Ultimate Path to Success Starts Now!

Color coding of peripheral IV catheters provides a quick visual cue for the lumen size. The gauge number relates to the diameter, with smaller numbers being larger lumens and larger numbers being smaller lumens. To speed recognition, manufacturers assign colors to gauges. In the commonly used scheme, blue identifies 22-gauge catheters, which are smaller than 20-gauge (often pink) and larger than 24-gauge (often yellow). So, blue is the color you’d see for a 22-gauge IV catheter.