Where is the purple arrow located that appears when i am using GPS?

-Preferences.app does not work. For reference though the image is called 'LocationActice.png' in preferences.app

I want to change this purple GPS arrow.

And another unrelatedish question: how do i access/find the com.apple.springboard? (Is there a program?). I only know of the folder through a couple downloaded themes.

iPhone 3GS 4.2.1