When Nike previewed their Crayola-box U.S. Open looks for Serena Williams, Rafael Nadal and Roger Federer last week, we thought it might have just been the sporty brand up to their eyebrow raising tactics -- the brand did outfit Andre Agassi back in the day.

But since opening day of the tennis tournament, we've been seeing some serious bold colors.

Serena Williams rocked Fuchsia by Nike, while sister Venus came back from a knee injury to win in a bright pink tennis dress featuring her specialized crest (above). Watch out, Federer, you have has some serious monogram competition!

Number seven seed Vera Zvonareva won easily in straight sets, pairing a classic red top with a maroon skirt, and Amelie Mauresmo donned a tennis dress in turquoise.

While she lost in the first round,18-year-old up-and-comer Gail Brodsky of Brooklyn, NY still lit up the courts with her bright yellow Nike top.

In other stylish U.S. Open news, Ralph Lauren returns as the tournament's sponsor. The ball boys and girls wore the iconic designer's bold red, white and blue diagonal stripe polo shirt.

For fans who'd rather score style points from the sidelines, RL is offering a cricket-inspired tennis sweater with chevron detailing and a women's "Matchpoint" tennis dress, which Christie Brinkley wore in the Hamptons over the weekend. The pieces are for sale at the RL store in the Arthur Ash stadium and online.

With all this color, are tennis whites a thing of the past? Vote in the poll and let us know in a comment!