New research suggests that feeling sad may actually change how people perceive color, The Washington Post reported.

Researchers found that the associations people make between emotion and color go beyond mere metaphor. The results of two studies indicate show that people who felt sad were less accurate in identifying colors on the blue-yellow axis than those who felt amused or emotionally neutral.

"Our results show that mood and emotion can affect how we see the world around us," first author Christopher Thorstenson of the University of Rochester said in a statement. "Our work advances the study of perception by showing that sadness specifically impairs basic visual processes that are involved in perceiving color."

Researchers collected and analyzed data from 257 undergraduate students.

In the first study, 127 participants watched an emotional film clip and then completed a visual judgment task. The participants were randomly assigned to watch an animated film clip intended to induce sadness or a standup comedy clip intended to induce amusement.

After watching the video clip, the participants were then shown 48 consecutive, desaturated color patches and were asked to indicate whether each patch was red, yellow, green, or blue. Researchers found that participants who watched the sadness video clip had a difficult time identifying colors than participants who watched the amusing clip, Time reported. They were less accurate identifying color patches that were on the blue-yellow axis. They showed no difference in accuracy for colors on the red-green axis.

A second study with 130 undergrad participants showed the same effect in comparison to a neutral film clip: Participants who watched a sad clip were less accurate in identifying colors on the blue-yellow spectrum than those who watched a neutral screensaver.

"We were already deeply familiar with how often people use color terms to describe common phenomena, like mood, even when these concepts seem unrelated," Thorstenson said. "We thought that maybe a reason these metaphors emerge was because there really was a connection between mood and perceiving colors in a different way."

The findings which are detailed in the journal Psychological Science, suggest that sadness is specifically responsible for the differences in color perception.