We've done some testing in another thread...
The latest DAE export format does assign the colors to materials in a way that an import into Blender or Sketchup recognizes correctly, but that MeshLab does not.
If a material has a texture then MeshLab will also recognize it correctly.
It seems that some applications fail to recognize the DAE's plain-colored materials, while others do not.
I have tested colored/textured material exports of DAE in v8 and v7 and find that there is no difference as face as MeshLab is concerned - the plain-colored faces do not get rendered.
Examining the two DAE files the material definitions appear virtually identical except for different 'IDs' - to be expected, and the v7 'Material1' name being substitutes with the 'real name' in v8.
So it seems to me that the 'plain-color' issue is MeshLab's and not v8's DAE format as v7 is all but the same... 'Blender' can cope