Color theory is a complex subject dealing with how color represented, interpreted by programs, generated by output devices, and perceived by humans. The articles here detail how Photoshop handles color theory.
“Every image has a colour mode. These modes differ in how many channels are used to represent a...Color mode
“A color profile determines how an output device (i.e. monitor, printer) will interpret the color...Color profile
“Color correction is the process of applying adjustments to an image to resolve variations in...Color correction