Set ArcMap's legend shade to match transparency

Summary

The legend symbol can display an opaque shade for polygons or marker symbols assigned transparency values.

Note:
At 9.3, the option to simulate transparency in legends is set on the Data Frame Properties > General tab.

By default, this setting is off (unchecked) for maps created with versions of ArcGIS prior to 9.3, but it can be turned on if desired. So when a 9.2 map is opened in 9.3, this setting will be off by default and visibly, there will be no difference between 9.2 and 9.3 in how the legends for transparent layers appear. This setting is automatically checked for new data frames created in existing map documents.

Procedure

1. In ArcMap, click Tools > Customize.
2. Navigate to the Commands tab > Categories > Page Layout > Commands > Eye Dropper.
   
   
3. Click the Eye Dropper, drag, and drop it onto a toolbar.
4. Click the docked Eye Dropper tool, click a polygon feature in the data frame, and click OK.
   
   

   Note:
   The color dialog box displays the color name in Red, Green, Blue combination. 

   
   
   

   Note:
   The displayed color will now be saved to the color palette style. 

   
   
5. In Layout View, click the Select Elements tool on the Draw toolbar.
6. Right-click the Legend and select Convert to Graphics.
   
   

   Note:
   If there is no legend in the layout view, add it by clicking on Insert > Legend. 

   
   
7. On the Draw toolbar, click Drawing > Ungroup.
   
   

   Note:
   Do this twice to completely ungroup the legend patches and text. 

   
   
8. Select the legend patch, which is now a simple graphic.
9. Click the Fill Color button on the Draw toolbar to open the color palette.
   
   
10. Click the recently saved transparent color in the color palette to apply it to the legend patch.
    
    

    Warning:
    The legend is now a graphic and is no longer linked to the data frame.