There is a company out there call Pantone, and their entire company is about selling color. They literally have a name, number and swatch for about every color there every was. Not only that, they have gadgets that can read a color and tell you its name and number.
Yea, so what? Well not only does this company sell color and color related products, they create forecasts of the next big color of the seasons. They analyze the markets in fashion and homes. Based on that they give out their predictions every season.
So wonder why there is all of the sudden emerald green every where? It's not because of the new Oz movie (which was pretty good p.s.). It's because Emerald Green was named Pantone's Color of the Year for 2013, and was featured in both the spring and fall color trends forecasts.