Three British teens have won the top prize in the U.K.’s TeenTech Awards.

The teens, two 14-year-olds and one 13-year-old proposed an idea for a new type of condom that could detect sexually transmitted diseases amongst intimate partners.

The condoms will have antibodies on them that would interact with the antigens of STDs, causing the condom to change colors depending on the disease.

For instance, if the condom were exposed to chlamydia, it might glow green — or yellow for herpes, purple for human papilloma virus and blue for syphilis.

The proposal enabled the trio to win the top prize in the U.K.’s TeenTech Awards, and they have already reportedly been approached by condom companies.

However, there are some imperfections. It is unclear whether the STIs would be detected in just the user’s partner or also the user as well.

In addition, there’s the awkward question of what would happen if the condom came into contact with two or more STDs—not to mention the logistical difficulties of figuring out a way to determine the color with sufficient opportunity to make use of those findings.

Via Time