Pantone is a company based in New Jersey. Their business is color. Their primary product is a series of color cards (similar to paint chips in some ways) that are used by many industries to color match products in production. What does that mean? That means that a company in California can have a manufacturer in Texas (or China) make a product, and when the company tells the manufacturer that they want a pair of shoes made in Pantone 18-1438 (which is the color code for Marsala), they know they'll get exactly what that.
This product put them in a great position to coordinate trends. Twice a year, Pantone gathers international color experts and after a two days, colors are selected for upcoming seasons and years. These colors both predict and dictate what will later appear on runways and high fashion lines before trickling down to all portions of the fashion market. (If you're interested in an entertaining movie, I recommend watching The Devil Wears Prada, as there's a very memorable scene on this subject.)
What does this mean for you? Well, it makes it easy to pick out an accent or new staple piece that you know will be on trend, as long as you know what's coming up!