I successfully changed the background color of the body, but I haven't been able to adjust the white background color of the page.
Here's my (currently new and empty) blog, and here's my edited CSS:
/* Begin Typography & Colors */
font-size: 62.5%; /* Resets 1em to 10px */
font-family: 'Lucida Grande', Verdana, Arial, Sans-Serif;
margin: 0 0 20px 0;
thanks to anyone who can help me out with this.