The water is no place for summertime blues.

Nikki Scarnati, a certified infant swimming instructor, uploaded an alarming video on TikTok to share the dangers of wearing swimwear that matches the water — warning parents that kids could be too camouflaged to rescue.

To demonstrate, Scarnati filmed her young daughter swimming in a pool, wearing a blue one-piece bathing suit. In the video, which has been viewed over 4.6 million times, the girl’s blonde head could be seen bobbing on the water’s surface, slipping under every now and then. But the cerulean hue of her swimsuit makes it near-impossible to see the rest of her body.

The Spring Hill, Tennessee-based teacher noted she’d purchased the swimsuit for her daughter for the purpose of the video, pointing out how hard it was to spot her daughter in the water because it’s the “same color as our environment.”

“This is why you do not put your children in blue bathing suits. Look at how difficult it is to see her under the water,” Scarnati explained “And this is in calm water. This is not with a whole bunch of other kids playing and splashing around and having a good time.”

“So, do not buy blue bathing suits, guys,” she begged, suggesting parents “buy bright ones” instead.

Commenters agreed, thanking the mom and instructor for her advice.

“I’m a former lifeguard and this is absolutely right!” one user commented. “Any shade of blue is difficult to see, and so is any pastel light color in general.”

“That’s crazy I would have never even thought about it wow,” another wrote.

“I teach swim lessons. Proper colored suits are one of the things I require,”

“I never would’ve never thought of this. Thank you,” gushed another.

According to the Center of Disease Control and Prevention, drowning is the second leading cause of unintentional injury deaths for children aged 0-17 years and the leading cause for those aged between 1-4 years.