You can control the fading effects in AutoCAD with the following system variables:
For in-place editing on external references (which also works on edit-in-place blocks), the Xfadectl system variable adjusts fading effects. For objects on locked layers, use the Laylockfadectl system variable. For entire xrefs, use the Xdwgfadectl system variable. Note that tip #4070 includes a small LISP routine to toggle the value of this variable. Xdwgfadectl and Xfadectl can be modified from the display tab of the Options menu.
Notes from Cadalyst tip reviewer R.K. McSwain: Many users set these variables once and forget about them, but some users like to enable, disable, or adjust these at various times. Knowing the system variable name helps you create a button or macro to make the switch quickly instead of going through dialog boxes.