We know the coordinates of the vertices and the color of each part, e. g. in such a way Graphics[{EdgeForm[Black], Red, Polygon[{{0, 0}, {0, 2}, {2, 2}, {2, 1}, {3, 1}, {3, 2}, {4, 2}, {4, 0}}], EdgeForm[Black], Green, Polygon[{{0, 2}, {0, 6}, {3, 6}, {3, 4}, {2, 4}, {2, 5}, {1, 5}, {1, 3}, {2, 3}, {2, 2}}], EdgeForm[Black], Blue, Polygon[{{1, 3}, {1, 5}, {2, 5}, {2, 3}}], EdgeForm[Black], Red, Polygon[{{3, 2}, {3, 6}, {5, 6}, {5, 2}}], EdgeForm[Black], Green, Polygon[{{2, 1}, {2, 4}, {3, 4}, {3, 1}}], EdgeForm[Black], Green, Polygon[{{4, 0}, {4, 2}, {5, 2}, {5, 0}}]}]
.
Graphics[{EdgeForm[Black], Red, Polygon[{{0, 0}, {0, 2}, {2, 2}, {2, 1},
{3, 1}, {3, 2}, {4, 2}, {4, 0}}],
EdgeForm[Black], Green, Polygon[{{0, 2}, {0, 6}, {3, 6}, {3, 4}, {2, 4},
{2, 5}, {1, 5}, {1, 3}, {2, 3}, {2, 2}}],
EdgeForm[Black], Blue, Polygon[{{1, 3}, {1, 5}, {2, 5}, {2, 3}}],
EdgeForm[Black], Red, Polygon[{{3, 2}, {3, 6}, {5, 6}, {5, 2}}],
EdgeForm[Black], Green, Polygon[{{2, 1}, {2, 4}, {3, 4}, {3, 1}}],
EdgeForm[Black], Green, Polygon[{{4, 0}, {4, 2}, {5, 2}, {5, 0}}]}]
Addition. The following result in green
is not a polygon so is not allowed.: