Why is this so important? Because your website and all of your marketing material is not about YOU or what colors you like but rather about what your visitors or customers like. The purpose of your website and marketing materials is all about attracting and invoking a certain feeling in your visitors, which has nothing to do with you. This often seems to be difficult for business owners to understand, yet it is critical for business success.
Example, if your target audience is all male, you can use darker colors and colors with deep contrast. Women tend to prefer softer shades of color but again it depends on what your website is all about and what you are trying to get your visitors to feel and do.
Different colors can cause people to feel: relaxation, happiness, agitated, energized, calm, mellow, angry, feel like shouting, a statement was made, authoritative, professional, trustworthy and more.
Since most websites have more than one color in them, the colors need to have similar hues to them and be coordinated for a good appearance.
To understand the colors that website designers use, try using http://kuler.adobe.com/#themes/rating?time=30 to help develop your color scheme.You will also want to read more on how colors affect emotions at www.color-wheel-pro.com/color-meaning.html.
Maximize your website and your marketing to your niche or target audience by paying attention to the colors you use and you will increase your business success.