+salsaturation You don't need to do anything like that it is far easier it is an option within the theme. The theme has a built in custom CSS area anyway.
+nicksvicks, Go to Suffusion Options > Other Graphical Elements > Miscellaneous and it is the first option on the page.
It is well worth exploring all the in-built theme options ;)
You normally get a better faster response over on the official support forum at http://aquoid.com/forum/