This isn't a big deal and can be achieved with some simple CSS, our staff have already provided you with the required information on how to achieve this.
However, you seem to be confused over the containers, classes and how to correctly write the CSS. You shouldn't use content-pad for altering the background color for a section, this container is for padding control and nothing else. If you wish to add a background image/color to a container of a section etc.. you should use the content container.
Also sections have a similar div/container structure for example:
and so on...
If you wish to style a section on a specific page, then you will need to use the unique class for that page/post that is added to the body class.
For example, lets imagine that you have a page with an ID of 2 and wish to have the branding section with a red background. You would add the following code to your custom CSS:
Depending on your Customisation method, you may be required to use one of the PageLines overrides, see here for more information -
If you wish to add a background color or image to the Branding section globally, then you remove the page-id-2 from the custom CSS and use the following:
Note that I have added a PageLines override in the CSS (#site).
The following code can be used as a template for nearly all sections including the content section. Simply replace the .section-branding with the correct class for that section. You can find the correct class by using either FireBug or your browsers built-in tools, inspect the section and look for the class, the class is located in the
<section ID="" class="">
See the image below, which is for the Branding section: