A Kentucky high school student was expelled from a Christian school after administrators saw a photo of the girl from her 15th birthday wearing a rainbow sweater posing next to a rainbow cake, according to the girl’s mother.

Kimberly Alford claims her daughter, Kayla Kenney, was dismissed from Whitefield Academy in Louisville, Ky., where she was a freshman, after the photo was posted on social media earlier this month.

“She was happy. She looked beautiful,” Alford told WAVE of Louisville. “Of course, as a mom, I took her picture blowing out her candles, and I posted that on my Facebook page.”

But following the birthday post, Alford says she received a letter from the school claiming the picture was not inline with the school’s policies.

“The WA Administration has been made aware of a recent picture, posted on social media, which demonstrates a posture of morality and cultural acceptance contrary to that of Whitefield Academy’s beliefs,” the academy’s head of school, Bruce Jacobson, wrote in the letter. “We made it clear that any further promotion, celebration, or any other actions and attitudes that are counter to Whitefield’s philosophy would not be tolerated. As a result, we regret to inform you that Kayla is being dismissed from the school immediately.”

Although rainbows have been a symbol of gay pride and acceptance over the decades, Alford says her daughter’s matching rainbow cake and sweater were coincidental.

The Whitefield Academy’s handbook says the school seeks to “mold students to be Christ-like.”

“On occasion, the atmosphere or conduct within a particular home may be counter or in opposition to the Biblical lifestyle the school teaches,” the handbooks states. “This includes, but is not limited to, sexual immorality, homosexual orientation, or the inability to support Biblical standards of right and wrong.”

In a statement to NBC News, the Whitefield Academy said the photo was one of several violations carried out by the teen.

“Inaccurate media reports are circling stating that the student in question was expelled from our school solely for a social media post,” the statement said. “In the fall, we met with the student to give her a final chance to begin to adhere to our code of conduct. Unfortunately, she did not live up to the agreement.”

Alford says the school immediately denied her appeal to the expulsion, but the Whitefield Academy agreed to remove it from her transcript and change it to a voluntary withdrawal. The freshman has since relocated to a new public school.