
I like Dashboard's Stickies widget, and use it all of the time, but I wanted some colors other than pastels. For example: a bright red one that would jump out at me for "to do" items.
I found it pretty easy to do by going to /Library/Widgets/, then control-click on the Stickies.wdgt and select Show Package Contents from the pop-up. Next, open the Images folder, and you'll find the images used for the stickies colors. Open the pink.png (or some other color that you don't use) with Photoshop (or your favorite graphics editor), and save it as a copy on the desktop called red.png. Then use the paint tool and paint it red or whatever color you like; I even added a gradiant effect. Save your changes, and copy it back into the Images folder, typing your password when prompted.
Next you'll need to back up the original pink.png and replace it with the red one using the following commands in the Terminal:
$ cd /Library/Widgets/Stickies.wdget/Images
$ sudo mv pink.png oldpink.png [enter your password when prompted]
$ sudo mv red.png pink.png
Open a stickie and select the pink color, and you now have a red stickie pad. If you ever want to change it back to pink, just swap the oldpink.png with the pink.png in the Terminal.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20050516234420283