To invert colors on an iPhone, you'll need an iPhone 5s or later, running at least iOS 11. Since the iPhone 5s dates back to 2013, and iOS 11 to 2017, compatibility shouldn't be a problem.

starting with the iPhone 5s (September 2013). Using two LEDs; one white, one amber, they are not designed to give off more light but to color correct the ambient light in the room for more ...