Screen Color not changing

After numerous successful previous background color changes, I now can't get
the color to change. I've tried two ways: 1) Control Panel, Appearances &
Themes, Display, Desktop, Color, Apply, and 2) Click on desktop, Properties,
Appearance, Advanced, Item, Application Background, OK, Apply. In either
case, upon clicking Apply, the system goes through the wait mode as if it's
applying the change, but in the end, the color hasn't changed (although it
appears with the new color in the Appearances table). When going through
method #2 above, and reviewing every "Item", none of them show the color that
I'm currently seeing as the background on any screen. Any insights would be
appreciated!