For music, it turns out that humans are really wired to associate the emotions they feel with colors. Scientists in UC Berkeley found this out when they subjected 100 participants to 3 experiments making them listen to 18 pieces of classical music composed by Johann Sebastian Bach, Wolfgang Amadeus Mozart and Johannes Brahms (that differed in being slow, medium, fast and in major and minor keys) and made them pick the color they “see” from a palette of 37. Half of the participants were from the Bay Area and half were from Guadalajara, Mexico. For the first one, vibrant colors were always associated with upbeat music and major keys moving to dull to darker colors for sad music and minor keys. For the face and color experiment, the subjects were asked to pick the color that matched a facial expression. As predicted, the more vibrant colors (oranges and yellows) were associated with happy faces, while the darker ones with sad, angry faces. For the last experiment on music and faces, the same associations held true.
The study by Stephen Palmer, Karen B. Schloss, Zoe Xu and Lilia R. Prado-León was published online in the Proceedings of the National Academy of the US last May 13, 2013.