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In[526]:=
gg = Graph[{1, 2, 3, 4, 5, 6}, {UndirectedEdge[1, 2],
UndirectedEdge[2, 3], UndirectedEdge[3, 4], UndirectedEdge[4, 5],
UndirectedEdge[5, 6],
UndirectedEdge[6,
1]}, {VertexStyle -> {2 -> RGBColor[0, 1, 0],
1 -> RGBColor[0, 0, 1], 5 -> RGBColor[0, 1, 0],
6 -> RGBColor[1, 0, 0], 4 -> RGBColor[0, 0, 1],
3 -> RGBColor[1, 0, 0]}}];
In[527]:= PropertyValue[gg, VertexStyle]
Out[527]= {3 -> RGBColor[1, 0, 0], 6 -> RGBColor[1, 0, 0],
5 -> RGBColor[0, 1, 0], 2 -> RGBColor[0, 1, 0],
4 -> RGBColor[0, 0, 1], 1 -> RGBColor[0, 0, 1]}
