We never Realize our palette when running inside of plugin. This causes
incorrect colors in plugin applets when running in 256-color mode.

I've attached a test case, Gradient, which can be used to see some of the
problems. The test draws a red rectangle in the top third of the applet
and then a gradient fill left-to-right in the bottom part of the applet
(black-to-red). The test should be run inside of the plugin and various
window manipulations should be perfored to see the gamut of problems:
try making the browser the active and the inactive window (preferably
with the other window having its own color palette) and try
obscuring the painting region to make it a complex region instead
of a simple rectangular region.

The problems vary between platforms, but here are some of the effects I've
seen (running with the attached Gradient test case):

Win98:
Netscape 4.7: Rectangle Black (not red), Gradient fill wrong when
gradient area is partially obscured
IE: Rectangle Black, gradient fill wrong when unobscured but
window inactive and when area is obscured (active or inactive)

Win2K:
Netscape4.7: Gradient looks good, but the colors in the gradient are
too simple when the area is obscured
IE: Rectangle is fine, but gradient wrong when unobscured/inactive and
gradient too simple when the area is obscured.