Jerry, you probably need to open the Fill and Stroke toolbar under Objects at the top of the screen. Select your object (the rectangle) then click on the Fill tab in the Fill and Stroke toolbar. You should see that you have the checkerboard pattern selected. Near the top of that toolbar you should see an X and 4 boxes. The last box is for patterns. Try clicking on the first box. That box should give you a solid color. Then all you need to do is select the color you want.
I hope I didn't confuse you. I can post a screen shot if you want.