Fashion follows Hollywood. When Lindsay Lohan started trotting around Tinseltown in leggings, suddenly everyone started copying this style, much to the dismay of everyone's favorite fashion critics, and retailers across America struggled to keep an adequate spandex stock. Thankfully, it's not just the ridiculous trends that catch on -- when Ben Affleck gave Jennifer Lopez a 6-ct pink diamond engagement ring, there was a rush on pink diamonds (until the rest of the world realized that they were not movie stars and couldn't actually afford them). So then there was a rush on pink cubic zirconia.

The Bennifer engagement ring really sparked a big trend in Hollywood, and the rest of the world followed. Starlets no longer settled for traditional ring styles like round solitaires in Tiffany settings. Those rings are classic and glamorous indeed, but not unique enough to make a splash on the red carpet. Now we're seeing celebs with every color diamond in the spectrum, like JLo's pink rock, Heidi Klum's huge canary diamond, and Carmen Electra's black diamond ring, to name a few. In addition to the colored diamond trend, solitaires have gone the way of the dinosaur as celebs opt instead for much busier rings with lots of accent stones, and maybe even a non-diamond center stone, like the pink sapphire Nicole Richie received from ex-fiance DJ AM.