http://www.colorofmysound.com/Assign colors to songs at the free music promotion community, ColorOfMySound.com
"Synaesthesia is the mixing of the senses. Those affected by it hear colors, see sounds, and taste tactile sensations. When the two senses involved are sound and color, this phenomenon is no longer limited to synaesthetes: anyone, given a sound and time for contemplation, can ascribe color to that sound. Often, these connections between sound and color will overlap from person to person.
Color Of My Sound is an informal experiment to test that hypothesis. First, choose a sound category. Then, after listening, choose the color to which you are most strongly drawn. Give us your thoughts. Then, you can see how others voted for that particular sound. "