Some scientists in the United States did an experiment. They used a special light and looked into a machine. They saw a new colour. They called this colour "olo". The scientists say no one has seen this colour before.

The scientists used a laser to shine light into the eyes of five people. These people saw the new colour. The colour is blue-green. The scientists say it is very bright. People cannot see this colour outside without the special machine.

Some other experts are not sure if this is really a new colour. They say it is hard to know. But the scientists want to study more. They hope this can help people who cannot see some colours.