GPS Screen shots
Here are some screen shots taken from a GPS. The yellow colour is exaggerated - the real screen isn't nearly as yellow. It is the same colour you see with no maps loaded.
The first shot shows bush with a brighter green, and in patches. The second one shows the same area with a different customisation - this is 'lighter solid bush'. This lighter colour gives better contrast to the contour lines on the GPS. This shot shows the very clear red lines for tracks. The third picture shows West Arm of lake Manapouri. This shows the powerlines, buildings, roads, a stream and the cliffs.
Mapsource Screen shot
Below is a screenshot of the Okuku River, taken from Mapsource. This is typical of the detail that you can get in Mapsource.