Your browser does not seem to support JavaScript. As a result, your viewing experience will be diminished, and you have been placed in read-only mode.
Please download a browser that supports JavaScript, or enable it if it's disabled (i.e. NoScript).
C
It is probably just how SketchUp shades surfaces. You might try playing with the sun and shadows settings to see if you can get it to the level you would like. Do you have a small example file to look at?
Chris