The following video mainly focuses on how directors use color in their movies, but the same principles and reasoning can be applied to your still photography. It covers what some of the different colors are traditionally attributed to as well as how colors are affected by hue and saturation.
Part of what makes color theory so difficult to put your finger on as someone just dipping your toes in is that there are no set guidelines, color is used in different ways by different artists. The key is finding how you want to use color to bring out an emotion or reaction from your viewers and using it effectively to do that.
In all, this 16-minute video is a great little primer on how color works and using it effectively to tell your story. You can learn more about all of this through the free e-book that is also being distributed alongside the video. If you are interested in that you can find it here.