1.If the diagram is in a document or a worksheet, double-click on the diagram to open it.
2.Double-click on the fill.
3.Set the desired fill direction in the Fill Area field.
Note: If you use the Area between curve and Y axis or Area between curve and origin of X axis fill direction, on the Data tab of the Properties dialog box of the curve you should select the option Swap X and Y components. The curve is then no longer drawn from left to right, but from bottom to top instead, which matches this filling direction.