The background is important especially when you need to differentiate the selected contents from other contents. To add or change the background fill effects, please follow the steps below:
Step 1: Select the cell or the data range;
Step 2: Right click to bring up the dialog box, from the list, click "Format cells";
Step 3: In the "Format Cells" window under "Fill" Tab, click "Fill Effects";
Step 4: In the "Fill Effects" window, select color 1 and color 2, then select the shading styles;
Step 5: Click "OK" when finished.