Still window borders and bluish title bar on a standard JInternalFrame looks very bad (in my opinion), but this is not really what user will pay attention at. The only one thing left: remove Java logo icon on the left side of title bar.
Ah, and I've added fade-in and fade-out effects when my modded window appears and/or disappears. Not really important, but just feels more smooth.
Update: I had to go across the code a bit to make sure now it works as should be on Slowlaris (2008.11, running on the same xVM). Nimbus default theme from Gnome looks pretty clear and not that bad. Default Java 6, Update 10 is a pleasant thing. Yet I am not getting why there on
JInternalFramethat small Java logo is rendered *twice* on a title bar: once crappy, with extra-garbage pixels (on left) and once pretty good, near the title actually. Well, probably must be a Sun advertisement of their flagship trend...
Here how it looks like (no change much from previous shot above):
P.S. Damn, anybody wants to make it works on Windows?... :-(