At the moment the design is quite busy, try to keep things as minimal as possible and give the focus to your products. Now if I get to your homepage the attention goes to all sorts of things, twitter, free shipping the cart. But not to the products and those are the ones you should promote. All the other things should be just extra or to give a customer the final push. I think the theme and the colors are ok, but there are some inconsistencies or minor flaws. For example: the top navigation isn't rounded at the right side, there are only three "aanbevolen producten" so the spot on the right is empty, not all the colors are consistent and you are using the default favicon. You are on the right track I guess but the store could use some work in my opinion. Edit: "Kaart lezers" should be one word.