As a graphic designer in Panama City, FL, I get asked this a lot. We all know colors are important for a variety of reasons, one of the most important in regards to marketing is the emotional reaction they invoke when viewed. Using the correct colors can help create the emotional reaction you want from prospective customers. User the wrong one, and just as with branding it can turn-away customers/clients as they sense something is just off about the message.
Here is a breakdown of colors and the emotional reaction they solicit from people.
As a fun exercise, learn at least one of these and the next time you see it used heavily in a design or building think about the emotion they want you feel, and if it is successful. For instance, if you ever eat at McDonald’s (not recommended) they recently started adding greens and other natural colors to there advertising and packaging. Why might you ask? To try and re-associate itself as a healthier brand while simultaneously offering healthier options. Just food for thought.