Hello
1. The CSS needed to change the background to your module position would vary depending on the modules. For the base modules and footer area try adding the following to the Custom CSS field of your templates parameters...
[code type=css]#container_base .wrapper960, #container_copyright .wrapper960 {background: #000000;}[/code]
Where #000000 is your new background colour (edit to taste).
2. Top change the menu item size (top menu) also add the following..
[code type=css]#hornav ul a, #hornav .separator {font-size:12px}[/code]
Where 12px is your new font size (edit to taste).
3. With every module in Joomla you will find a 'Module Class Suffix' field under 'Advanced Options' in your modules parameters. Simply add the suffix of your choice (
http://demo.joomla51.com/0093/index.php/features/module-variations) in this field to apply the alternative styling to your module.
CiarĂ¡n