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.

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.