Neon is a colorless gas that glows bright reddish-orange when electricity passes through it. Scientists discovered neon in 1898 by cooling air until it turned liquid, then carefully separating the different gases that make up our atmosphere. Neon is one of the noble gases, a family of elements that rarely react with other chemicals.

You've probably seen neon's glow in signs outside restaurants, theaters, and shops. These neon signs became popular in the 1920s and created that distinctive colorful glow we associate with diners and old movie theaters. While people call many bright signs “neon,” true neon glows reddish-orange. Other noble gases create different colors: argon glows blue-purple, and xenon glows blue-white.

The word neon has also become an adjective describing super-bright, attention-grabbing colors that seem to glow, like neon pink or neon yellow sneakers. These colors don't actually contain neon gas, but they're so intensely bright that they reminded people of those glowing signs. When someone wears a neon green shirt, it means the color is so vivid and eye-catching that it almost seems to shine.