Hybrid propulsion systems warrant further investigation due to their inherent safety and performance benefits. Testing and evaluation of high-performance cryogenic oxidizers for use in hybrid motors is uncommon as a result of the complexities of working with cryogenic fluids and the safety concerns of working with oxidizers. Liquid nitrogen (LN2) is a safe analogue for liquid oxygen used for testing cryogenic systems, but retains cryogenic complexity and requires separate pressurization. Self-pressurizing oxidizers stored as a superheated liquid, such as nitrous oxide (N2O) and its safe-testing analogue carbon dioxide (CO2), have seen widespread use resulting from the simplicity of not requiring added pressurization. An experiment to compare the injection characteristics of superheated CO2, subcooled CO2, and LN2 was performed to evaluate if superheated liquids can be used as an analogue for the flow visualization investigation of cryogenic subcooled liquids. High-speed imaging and shadowgraphy techniques were used for imaging the injected atomization patterns for nine test cases, a combination of the three tested fluids with three different step distances. These images were analyzed based on the reduction of brightness due to the blockage of light from the injected fluid to determine if spray patterns and recirculation zone formation were comparable. It was determined that CO2 in varied phase-states could be used in place of cryogenic liquids depending on the region of interest. Jet formation of LOX was found to be closely emulated by both saturated and externally-pressurized CO2, whereas recirculation visualization of LOX was found to be emulated by externally-pressurized CO2. However, CO2 was found to be unsuitable for the investigation of LOX behaviour within the fuel grain center bore.