Yes. Shift + right click on an interior wall to bring up the House Interior Options panel.
At the top, you'll see options to change carpet colors for each floor (larger homes will have more floors) as well as the price for each selection. Cycle through the colors, your carpet will change colors allowing you to preview your choice. You will need to access the options panel on the floor with the carpet you wish to change if you want to preview it, although any carpet can be changed while accessing the menu from any floor.