Prince Louis Sports Throwback Prince Harry Look for Buckingham Palace Balcony Debut

Prince Louis sported a throwback Thursday and didn't even know it! The little royal is carrying on a family tradition and fans are loving it.

The son of Prince William and Kate Middleton — who celebrated his first birthday in April — made an appearance with the rest of the family on the Buckingham Palace balcony during the Trooping the Colour celebrations wearing a hand-me-down from his uncle Prince Harry.

The blue and white outfit was worn by Harry back in 1986 at the same celebration. He showed off his adorable outfit in the hands of Princess Anne while he and his mother, Princess Diana as they greeted the crowd.

Not just that, but this outfit that shows off the cream lace style, is a similar outfit to what both William and older brother Prince George wore during their first Trooping the Colour celebrations as well.

It's safe to say this outfit has become a traditional one. Click here to see the photos.

Meghan Markle took a break from maternity leave to attend her first Trooping since welcoming her first son Archie.

Prince Louis' outfit isn't the only thing people were talking about during their appearance. Royal watchers noticed a change in his mom's necklace she was wearing.

Her cross necklace that she's worn several times in the past, had a noticeable change to it: the diamond bail features a ball that connects the chain to the cross, where in the past, that ball was not there.

"It could be that Kate was gifted a diamond she wanted to add, or had another piece she no longer wore but wanted to keep the diamond, so transferred it over," Leora Moreno — who is a jeweler — said.

"The only difference is the additional diamond at the top of the cross, which could have been easily added at a later stage," the jeweler mentioned.

"Also, sometimes people just want to refresh their jewellery and this would be a great way to add to it but still keep the original design," she added.

Another jeweler, Arabal Lebrusan, agreed, saying, "This is a very simple way to to transform an old piece to make it more contemporary."

She continued by saying, "Such a delicate pendant works perfectly with the light yellow tailored dress, not making too big a statement, but just adding enough to be eye-catching. With such a statement hate choice, it is important to keep other jewellery pared down."