Beyonce made her first appearance since giving birth to baby Blue Ivy on Monday night in New York City. Even though the new mama left her baby at home, she brought a reminder of Blue Ivy with her - cobalt blue nail polish!

Beyonce went to husband Jay-Z's 40/40 to celebrate his first performance since having their child at Carnegie Hall. It was the first time the hip-hop king performed at the famed New York City venue and Beyonce made sure to be by her man's side.

But the 30-year-old new mommy made sure to add a hint of something to remind her of Blue Ivy at home. The singing diva rocked bright cobalt nail polish on her fingernails, which complemented gold jewelry and a red Alice by Temperley curve-hugging dress.

Check out Beyonce's blue nails called Baker Street by Nails Inc. I love this color! Lisa Logan, Beyonce's manicurist, tweeted on Tuesday afternoon.

Nails Inc. Baker Street polish is not yet available, but there are some options currently on the market similar to the brilliant blue. Nails Inc currently has three similar shades available - Belgrave Place (£11), Serpentine Road (£11) and Connaught Sqaure 3D Glitter (£11). Click here for purchasing information.

Other brands have some striking blues as well, inlcuding: Ulta's Blue Streak (Ulta, $6), Essie Go Overboard (Cusp, $8), Nicole by O.P.I Spring Excel (Target) and butter LONDON 3 Blagger (Dillard's, $14). 

The stunning cobalt blue hue was a nod to Blue Ivy, who was also recognized with a small IV tattoo peeking out from under the ring on Beyonce's left-hand ring finger.

The singer also wore Ofira & Lorraine Schwartz jewelry, a gold Alexander McQueen clutch and Christian Louboutin heels.

It was a late night for Jay and Bey, who stayed out until 4:30 a.m. They were sitting on the top tier of same seating the entire night, just laughing, eating food -- the chef at the club is Jay-Z's personal chef as well and he sent out salads to them at 2:30 a.m., a source told Us Weekly. Beyonce did have a martini at another point in the night, but she barely sipped it.

Towards the end of the night she was sitting with two of her friends and took out her phone, the source added. She was showing them pictures -- she was gushing and smiling and her friends were doing the same. She was very happy to be there, she had a lot of security.