A new hair color isn't the only thing Kim Kardashian flashed her nearly 13 million Twitter followers on Monday.

PHOTOS: Kim Kardashian's best hair looks

While shooting a campaign for the upcoming Kardashian Kollection swimwear line, the 31-year-old reality star snapped a pic of herself posing in a cleavage-boosting bikini top.

"Photo shoot fresh! All about corals for spring swimwear," she tweeted along with the sexy picture.

In a second image, Kardashian wears a fluffy white robe while still revealing the bright bikini. "Last shot of the day! On the set of our new Kardashian Kollection for Sears shoot!" she wrote.

Later on she asked fans what they thought of her light brown highlights.

"I dyed my hair lighter yesterday! I'm loving it! New hair color = new beginnings for me. You like?"