You've found an image that persuasively communicates your brand, and now you want to build a website around it. Here's how you extract the color palette from that image so that you can build frames, backgrounds and text that matches (cut and paste the link into your browser after you read this):
http://www.colourlovers.com/photocopa
You'll have to sign up to the site in order to use the tool, but this involves no more than establishing a user name and password. Once you're signed up, navigate to the "photocopa" page, click "photo" (just under "publish" at the top right), and type in the url of the image you want to use. You instantly get a range of colors found in the image, expressed as small samples to the right on your screen. Pick on various samples or on the image itself to create a palette at the bottom left. Clicking a small icon at the top right of each palette swatch gives you the Hex, RGB and HSV codes.
If you ever wondered how graphic designers matched color, there's your answer.