How to: Change the color of the floor in a 3-D chart.
Solution:
Click on the floor of the chart, select the 'Format' menu and select 'Selected Floor...'. Select a color.
1) Double-click on the chart. (A striped border with handles appears around the chart.)
NOTE: If the chart is on a separate chart sheet in Excel, click the tab for the chart sheet.
2) Click once on the floor of the chart.
3) Select the 'Format' menu and select 'Selected Floor...'. (The Format Floor dialog box appears.)
Format Floor box
NOTE: By default, the floor appears as a gray, shaded area at the bottom of data markers.
4) Select the desired color for the floor from the 'Color' palette of the 'Area' group.
5) Click 'OK'.
