An infusion system having a priming detection system to indicate that a component of the system, for example a cannula or needle, is primed with a fluid to be delivered into an individual's body. The infusion system utilizes a reactive element that reacts with the fluid or at least one component of the fluid to be delivered, to produce a color change or a colored complex. The reactive element can be deposited, coated or otherwise incorporated in any component of the infusion system that would benefit from a visible indication of a primed fluid, including, but not limited to a tubing, infusion set, cannula, needle and/or guard element at least partially covering or surrounding a cannula or needle. The visual indication improves the user experience during the priming and filling of the system by providing a clear color change confirmation upon priming completion and prior to insertion into the body.