At the moment i'm doing a spectral series of different colours and their associated meaning. I believe colour can influence our emotions as well as the way we act and how we respond to people, things and ideas.

Some examples:

Example 1
Patents suffering from depression in a mental hospital were placed in rooms with bright yellow or red walls, and hyperactive patients were confined to rooms with walls of blue or green.

Result
Patients appeared more relaxed and had significant reduction in blood pressure.

Example 2
The Blackfriars Bridge, in the heart of London, was a gloomy black structure known for its high record of suicides. The bridge was painted a bright green.

Result
The suicide rate declined.

Example 3
A group of men were placed in a red room, and another group were placed in a blue room.

Result
The group in the red room overestimated the length of time they had spent in the room, while the group relegated to the blue room underestimated the time that had elapsed.

Example 4
A group was invited to a dinner party where specially designed lightening equiptment had been installed. WHen the food was served, the normal incandescent light was switched to other illuminants which made the juicy brown steak look bright, the crisp green lettuce turn dull, the coffee a sickly yellow.

Result
Most of the guests could not eat, and those who did became nauseated.

Example 5
Workers in a factory complained about the weight of their metal tool kits, which were painted a dark brown. The management was advised to repaint the boxes in pale green.

Result
THe complaints ceased, and several men commented on the ease of lifting the new lightweight kits. Dark coloured objects are perceived as being heavier than light coloured objects.

^{Examples from Design Graphics Issue 60, July 2000}