It is easier to create your customized webshop by using colors that exactly match the design of your current website or images. Instead of picking colors you can also set the exact colors by entering Hex color codes. This are codes like for instance: #000000 which is the color black or #ffffff for white. If you do not know which colors to use but you have an image of the colors you want to use then you can use this online tool to create a color palette: http://www.pictaculous.com
This solution will give you the Hex colors of your image so you can use them as the colors of your webshop:
Example: