A new study found that feeling sad limits how well we see colors on the blue-yellow axis.

Earlier this summer another study looked into the late appearance of the color blue in societies around the world.

Feeling Blue and Seeing Blue: Sadness May Impair Color Perception

Humans didn’t even see the colour blue until modern times, research suggests

The new study on our ability to see blue when sad suggests a dopamine link. I wonder if dopamine is also linked to the appearance of the color blue in modern times.