AutoCAD allows you to adjust the transparency of hatching.
Below is an image with the transparency displayed, the hatch on the left transparency is 28% and on the right its 84%.
Below the transparency displayed has been switched off.
If the transparency tool for Hatch in AutoCAD and its stopped working then see the following:
This can be controlled by a system variable TRANSPARENCYDISPLAY.
This controls whether the object transparency is displayed.
0 Object transparency is not displayed.
1 Object transparency is displayed.
Please note this is only available in AutoCAD 2011 version onwards.