OK, so I tried changing the background color of my Calendar widget because the Theme I am using (Nextheme on CM6-RC2) has black text on a transparent black background. Kind of hard to read.
So what I did was copy the CalenderProvider.apk from the system/apps folder to my SD card, then from the SD card to my PC.
On my PC, I extraced the files, and opened the res\drawable-hdpi\appwidget_bg.9.png file (which is the background for the widget) using Paint.NET.
From there, I altered the background color (in Paint.NET, of course), saved the changes back to the extracted files from the original .apk, then replaced the original appwidget_bg.9.png file with the modified file within the archive of the original .apk (all of which I did on my PC).
From there I copied the new modified CalenderProvider.apk from my PC to my SD card, then using Root Explorer, pushed it to the system\apps folder to replace the original.
After that, I changed the permissions, and used terminal emulator to re-sync, then rebooted.
Upon rebooting and applying the widget to my homescreen, the background is the color I modified it to, but it is smaller, and the text runs outside of the borders of the new/modified background.
What am I missing here, guys? I tried increasing the size of the .png background within Paint.NET, but it made no difference whatsoever.
Here's the size and color it used to be
Here's what it looks like after modifying the png file