Dear Tiago, I am trying to use a matplotlib colormap for coloring vertices, and I need transparency also. import graph_tool.all as gt import matplotlib.pyplot as plt import matplotlib.cm as cm plt.switch_backend("cairo") g = gt.collection.data["karate"] position = gt.sfdp_layout(g) fig, ax = plt.subplots(1, 1) gt.graph_draw(g, pos = position, vertex_fill_color = gt.local_clustering(g), vcmap = (cm.inferno, 0.3), mplfig = ax) plt.savefig("test.pdf") I am getting the following error: Traceback (most recent call last): File "test.py", line 12, in <module> plt.savefig("test.pdf") File "/usr/lib/python3/dist-packages/matplotlib/pyplot.py", line 701, in savefig res = fig.savefig(*args, **kwargs) File "/usr/lib/python3/dist-packages/matplotlib/figure.py", line 1834, in savefig self.canvas.print_figure(fname, **kwargs) File "/usr/lib/python3/dist-packages/matplotlib/backend_bases.py", line 2267, in print_figure **kwargs) File "/usr/lib/python3/dist-packages/matplotlib/backends/backend_cairo.py", line 470, in print_pdf return self._save(fobj, 'pdf', *args, **kwargs) File "/usr/lib/python3/dist-packages/matplotlib/backends/backend_cairo.py", line 534, in _save self.figure.draw(renderer) File "/usr/lib/python3/dist-packages/matplotlib/artist.py", line 55, in draw_wrapper return draw(artist, renderer, *args, **kwargs) File "/usr/lib/python3/dist-packages/matplotlib/figure.py", line 1299, in draw renderer, self, artists, self.suppressComposite) File "/usr/lib/python3/dist-packages/matplotlib/image.py", line 138, in _draw_list_compositing_images a.draw(renderer) File "/usr/lib/python3/dist-packages/matplotlib/artist.py", line 55, in draw_wrapper return draw(artist, renderer, *args, **kwargs) File "/usr/lib/python3/dist-packages/matplotlib/axes/_base.py", line 2437, in draw mimage._draw_list_compositing_images(renderer, self, artists) File "/usr/lib/python3/dist-packages/matplotlib/image.py", line 138, in _draw_list_compositing_images a.draw(renderer) File "/usr/lib/python3/dist-packages/graph_tool/draw/cairo_draw.py", line 1565, in draw self.vorder, self.eorder, self.nodesfirst, self.kwargs) File "/usr/lib/python3/dist-packages/graph_tool/draw/cairo_draw.py", line 690, in cairo_draw vattrs, vdefaults = _attrs(vprops, "v", g, vcmap) File "/usr/lib/python3/dist-packages/graph_tool/draw/cairo_draw.py", line 484, in _attrs nattrs[int(attr)] = _prop(d, g, _convert(attr, v, cmap)) File "/usr/lib/python3/dist-packages/graph_tool/draw/cairo_draw.py", line 323, in _convert cmap, alpha = cmap ValueError: too many values to unpack (expected 2) However, if I remove vcmap argument, it draws fine. I am on Ubuntu 18.04, and the graph-tool version is 2.27. Kindly help me. Thank you Snehal Shekatkar Sent with [ProtonMail](https://protonmail.com) Secure Email.