Apparently when humans feel blue, they literally have more trouble seeing blue. Recent research in Psychological Science claims that sadness can negatively affect our perception of colors on the blue-yellow axis. It kind of makes you wonder whether the grass really is greener, right?

Interestingly, the researchers said they conducted the study because they wondered whether there was a reason why color-mood metaphors are so popular (Think: feeling blue, seeing the world through rose-colored glasses, painting the town red, tickled pink). “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,” Christopher Thorstenson of the University of Rochester, first author on the research, said in a Science Daily article about the study.

As it turns out, participants who watched sad video clips were less accurate in identifying blue-yellow spectrum than the people who watched funny videos. What’s crazy is the sad group had no trouble identifying colors in the red-green axis — just blue-yellow. Even when the sad group was compared with a neutral group, the same effect was found.

Who knows how the research will be used in the future, but if anything, next time you’re at an art museum you might be wondering if the person next to you is seeing the same shade of blue in that painting.

What do you think about this new research? Share your thoughts in the comments.