Consumer displays can do quite a good job matching colors if either (a) they have been characterized (either by a color measurement device or by eye by a carefu

Consumer displays can do quite a good job matching colors if either (a) they have been characterized (either by a color measurement device or by eye by a careful human observer with normal color vision) and the OS is set up to do proper color management using the resulting profile, or (b) the company producing them buys consistent parts and does careful Q/C. If you get a recent model iPhone, as an example, you are likely to get very close to the same output as every other iPhone, assuming you are in similar lighting conditions. Of course, human vision is quite sophisticated at adapting to various conditions, so the colors will not be precisely perceptually matching unless the observations take place in a standard setting. If one observer is sitting under a fluorescent bulb, another is in a dark room, and a third is sitting outside on a sunny day, all bets are off. There's also nontrivial inter-observer variation, even among people with normal color vision.