Windows Explorer Selected File(s) Inactive Background Color

I just have a quick question about Windows Explorer (in XP, but should be
roughly the same in all versions).

For work I am frequently working with large lists of files in Windows
Explorer, performing various operations on the files as deemed necessary, but
almost always in a sequential series one at a time. Does anyone know how to
change the color of the background color for the selected item when the
window is inactive?

I am frequently flipping back and forth between Explorer and the associated
program, and the default color (a very light off-grey) is hard to distinguish
from the unselected items (especially in Detail view).
I tried looking in the standard location (Display Properties -> Appearance
-> Advanced) but none of those items seem to affect the actual contents of
the Windows Explorer windows.
I also tried searching around on the internet and all I could find related
to my query is a few 3rd party programs that allow you to change all the
colors as you desire, but that is not a good solution as we are discurraged
from installing software on these computers at work.

There has to be some registry key I can tweak that will allow me to change
it to a darker color. If anyone out there can help, it would be a boost to my
productivity and help save my eyesight.

The advanced area should have a drop box you can set to "selected items" and
let you change the color.

Thanks for the input Mark, but that was not quite it...
Let me try to clarify the situation: (Please follow along so you can see the
issue)

-Open Windows Explorer (not in maximized view, so you can see some of your
desktop)
-Navigate to any folder that has 20+ files in it
-Change the view to 'detail' so the list can easily be sorted
-Select one file somewhere in the middle of the list
-Now, leave that file selected and click somewhere on the desktop so that
Windows Explorer is now an inactive window.

Now look at the file that is still selected in Windows Explorer. See that
the default background color for the selected item is a light grey? That is
the color I am trying to change. Your instructions only lets you change the
background color of the selected item while it is the active window.

I appreciate the help, and if you can find a solution that solves my real
problem that would be really great.

[rti]

To invalidate the highlight, it seems to send the LVM_SETSELECTEDCOLUMN message.
I wrote demo.