Over the years, I have visited literally thousands of web sites.  Every once in a while I will encounter one where my reaction to the color schemes they use is, “what they hell were you thinking”.

To all those people who seem to think designing a web site using the most bizarre combination of Crayola crayon colors is “cool”, let me offer a few observations:  yellow on green doesn’t work; green on light blue doesn’t work; yellow on orange doesn’t work; and orange on light blue doesn’t work. 

If the purpose of your site is to make people’s eyes cross, the combinations above will accomplish that goal.  If, one the other hand, you actually want people to read the information you placed on your site, you need to select high-contrast color combinations: black or dark blue on white; white on black or dark blue; black or dark blue on light gray; black or dark blue on light green; or white on dark red.

Generally, the best practice for choice of background color is to select one that offers the most pleasing appearance: white, light blue, light gray and so on.  If I happen to stumble upon a web site that screams at me with a bright yellow or puke green background I just have to assume the person that designed the site doesn’t want me to stay very long. 

When you design your background/foreground color combinations, or navigation buttons, use a combinations that are easy to read.  Every color has a “complimentary” color; that is, one that offers both a pleasing color combination and high contrast.

There are tools available to you on the web that will assist you with these selections.   Use your favorite search engine to find a site that offers "color wheel" combinations or "complimentary colors".
 

Let’s assume we wanted to design some high-contrast, visually pleasing navigation buttons.  Once you decide what color you want to use for the button you can then use one of these tools to find it’s complimentary color.  For instance, let’s say I wanted to use a particular shade of red for my button color.  The hex code for the red I want to use is #AF0A1A.  Entering that value into one of the tools gives the following complimentary color: #50F5E5.  The resulting button would look like this:
 


Using color combinations that provide your customers a pleasing visual experience will encourage them to look around and come back.  Using overly bright colors, or those that make the the text difficult to read is a surefire way to drive those customers away.