Colors can be used to brand your product or image. What are the color of Target, Home Depot, and United Parcel Service? These colors have been used with everything that can be seen to the public. The result is that we connect these colors with the company. Your site should be consistent in color use as well.
Here are two screen shots from different web sites. The one on the left provides information on things to do while visiting Waikiki. The page shown is the Honolulu Zoo page. The banner at the top is the well recognized Diamond Head volcano, some beach goers, and a hula dancer. This page has a couple of zoo animal images to connect you to the zoo. The other web site has a lot of colors, text types, and strikes some unwanted emotions. It seems to yell, “Get out of here!” even without the two fingers pointing the way out. To top it off, the site comes with complimentary music at full volume and without warning. The music seemed to add to the shock value with a one-two punch just before the knock out.
The bottom line with colors is to use complimentary colors that compliment the content of the site. There needs to be harmony between each color, and the colors need to be in harmony with the content. Do not be scared to use color to evoke the proper emotions that will help with the intended results of the site.