Shapes 3D effects can specify colors for extrusion and contours like
in the following example:

  <a:sp3d extrusionH="25400" prstMaterial="metal">
    <a:extrusionClr>
      <a:schemeClr val="accent5">
        <a:lumMod val="40000"/>
        <a:lumOff val="60000"/>
      </a:schemeClr>
    </a:extrusionClr>
    <a:contourClr>
      <a:srgbClr val="3333FF"/>
    </a:contourClr>
  </a:sp3d>

Colors can be theme-defined or set in RGB and can contain
transformations.

This patch preserves all the color information using the shape grab
bag and modifies an existing unit test to add this check.

Change-Id: Ida168affd4ca2135d0bd8f97135dc1cd1e74165a