I just came across another interesting colour site – www.colorexplorer.com
This site provides a free service – you can upload an image and the site will extact a colour palette from the image (you can specify how many colours you wish to extract). Palettes are notated in hex codes and RGB values.
I just tried with with one of my images and chose to extact three colours; the result is shown below:
If you want to use a photograph as an inspiration for interior design, for example, you can write down the RGB values and then go to www.easyrgb.com – this site allows you to convert RGB values into commercial paint codes.
A similar approach for websites: http://www.colorgorize.com