To setup the home page like the demo, first make sure you activated the 'Home' page type (go to Dashboard -> Pages & Themes and click the 'Inspect' button next to the theme. Then hit the Activate Files button if there are Page Types to be activated. Finally put the home page in edit mode and select the 'Home' page type. Then you'll be able to setup the home page like the demo.
To change the color scheme from the default red & blue to green & brown or orange & teal, simply change the line that says red-blue.css in the screen.css file (located in the theme files at corporateamerica/css/screen.css) to either green-brown.css or orange-teal.css.