Vertex Coloring in 2D and 3D
Mathematica 6 supports arbitrary shading gradients for 2D and 3D polygons.
In[1]:=  |  GraphicsGrid[
Table[Graphics[
Polygon[{{0, 0}, {1, 0}, {1, 1}, {0, 1}},
VertexColors -> Table[Hue[RandomReal[]], {4}]]], {4}, {4}]] |
Out[1]=  |  |