I like to do a lot of studying in color psychology, and when I teach a class on design I would always bring it up.
The problem is it’s so imprecise. The biggest difference amongst it are between different colors. For example, take the color red. As someone mentioned, it has very different meanings. In the west it’s generally associated with anger (“seeing red”) and is a very intense, sometimes negative, color. However, in China it represents life and vitality, so it is a very positive color.
However, even from person to person there can be a lot of differences with color. Some of these responses are instinctual and part of our genes.
An example of this would be the color blue. Blue, in most people, is an appetite suppressing color. This could be a developed attribute because there is little to no natural food that is blue (mold and stuff is also often blue, which we shouldn’t eat), so it’s instinctual.
Likewise, orange is an appetite stimulant in many people, likely because so many orange-ish foods are very nutrient rich (citrus fruits, honey, etc.). I’ve noticed a lot of fast food places have started adopting orange/brown color schemes, likely for this reason.
There are also color psychology which is developed individually. For example, if you had a favorite purple teddy bear growing up as a kid, the color purple may become associated with happiness, safety, or comfort… which isn’t a traditional response. Or, you may have been attacked by someone wearing a yellow raincoat and it was traumatic, so you begin associating yellow (which is normally a happy color) with fear.
It’s something interesting that I keep in the back of my mind when I’m picking colors, but not something I rely on.
I generally go with sets of shades that have a specific appeal. For example, I worked on a natural medicine website not long ago. I chose beiges and natural shades of green to get a “natural” effect. Likewise, if I’m working on a website for cutting edge, I’ll use lots of darker or unnaturally-vibrant and bold colors to get a more “high tech” feel.
When considering the effect of a color scheme, versus individual colors, the reaction seems to be more consistent (though not always if you have certain colors that have a very opposing and strong meeting, like red).