How do the Pros determine which trends will fade and which ones will rise?

So, the color orange has taken over. I see clothing,accoutrements, homes , etc., covered in this great color. I fell for it. I bought a jacket particulalrly because I liked (and still do) the orange details and am about to buy some stuff from CB2 that happens to have this color. Who makes the call that trickles down to the powers that be in all the related consumer markets so they deside in unison to use a particular color / palette of colors / motif (s) / etc. I saw The Devil wears Prada, but I would like a more insightful answer.