Web page design
If you decide to customize the look at feel of your web page, it could be enough to change the style/style.css file.
All the styles used in the public web page are defined here.
If you are used to working with CSS style sheets you will know what to do. If not, you maybe want to learn a little about it (see, for instance, W3C page about style sheets) but, in any case, you could be satisfied changing just the color of some elements in the page, which is quite easy.
If you take a look to style/style.css you will see that it is quite simple (we show here only an schematic structure, look into the real file for the details).