Dell Inspiron 1150.
Windows XP with black desktop background.
Randomly, the background goes to bright green.
But the windows logo and the media player icon
still have their RGBY segments in the correct color.
There's also a black smear trailing text and icons
that looks a lot like a drop-shadow.
The window backgrounds are still white, but there's a purple
effect that looks like a badly pixelated shaded area in areas
that might be shaded.

Everything still looks fine on an external monitor.

This has me baffled. If a color went missing, I'd expect it
to be missing..or full on... on all parts of the display.

Flexing the display cable by moving the lid has no effect.
Doesn't seem to be heat related.

What should I look for?
Thanks, mike