You can avoid Web programming with a simple trick: use Photoshop layers to construct a model of your design. Photoshop offers layers as a new feature in version 3. You can stack images on top of each other, and besides the least one (called background layer), all the layers behave like transparencies: their transparent parts reveal the layer underneath them.
To view your design with layers, follow the steps listed bellow:
Now you can get a better feeling for the color composition and potential problems with your designs. Saving the image as a flattened image in a common graphics format to send it to the client for discussion is another useful option.