Background colors are typically coded in the html directly. in "liquid blue" and the button styles are actually images tags (This method is specifically done so the tags such as Description, Shipping etc. do not get altered.) You can choose to NOT use the image tags and instead use pure text, change the font color, size and font style, but not everyone out there is going to have what you choose.
If you have a specific design in mind based off Liquid Blue, you can always contact the Auctiva Design Team and discuss a custom template design just for your use.