In CSS SCulptor, on the Box Tab, select the main container that these content areas will be placed inside. make note of the width of this container.
with that main container selected, click the plus button to add a new div, set the width of this new div to be 1/4 of the width of the container it is being added to, set the float to left
repeat this for the other 3 divs, on the last one, set the float to go to the right instead.
you can change the background color for the divs on the design tab.