If there is some electrical connector designated for the injector (you mentioned red and blue), get a voltage tester and see what the voltage is at the connector. Chances are it's 120v. There's no reason to make an injector that draws 220v unless you live in Europe. The 220 volts coming into the panel in your spa is split inside the control panel to 120V for smaller things like the circulation pump, transformers, lighting and other low draw items. I would guess the ozone injector would be included in that list. Usually the only things that run at 220v are heaters and jet pumps.