From the Insert menu choose Button
Bar then Horizontal, or click the appropriate button:
From the Format menu choose Fill.
On the Fade tab make the Start color
a medium blue and the End color a lighter blue. Set the
direction of the fade to go from left to right. Click OK.
Double-click the first button to see its properties then click OK. This stores the
button’s properties as the "Last Used"
attribute and allows you to quickly apply the same formatting to the other buttons.
Double-click the second button to see its properties. From the Last
Used list select the top entry (the formatting properties for the first button).
This applies all the properties from the first button to the second button.
Repeat Step 4 for each button in the button bar.
