background color for whole site

I can’t for the life of me figure out how to change the background color for the whole website.. including the content frames. I added ‘background-color: #’ line to the ‘body’ and the ‘html’ stanzas in the style.css file using Appearance -> Editor but it only changes the very background color that is quickly covered up by all the content frames. I tried also adding ‘background-color: #’ line to Appearance -> Theme Options -> Layout Options -> Additional Style but it has no effect. any ideas? Thanks!