<p>I have been trying to change the background color of Eclipse's windows to black and customize the font colors. There doesn't seem to be a way to do this, at least not in an obvious way. I am using version 3.3.</p>

<p>How do I do this or are there any plugin's that might be able to assist in doing this?</p>

If you go to Windows, Preferences then select General, Editors, Text editors, you can set colors on that property page (and there's a link for setting MORE colors - General, Appearance, Colors and fonts).
That's with an Eclipse 3.3 build anyway.