Hi I seem unable to control edge colors on my graphs. I have a graph with two vertex populations, A and B I have assigned colors according to a scheme that would normally provide four colors, as follows: Hierarchy tree: [ 0. , 0. , 0.2, 0.1] Edges from A to B: [ 0., 0., 0., 1.] Edges from A to A: [ 0., 1., 0., 1.] Edges from B to B: [ 1., 0., 1., 1.] All along the calculations I check colors with the constant result as follows: color {array([ 0. , 0. , 0.2, 0.1]), array([ 0., 0., 0., 1.]), array([ 0., 1., 0., 1.])} pen_width {1.0} … (As it happens this sample has no B to B edges) However, the final drawing shows as in the attached image, with a large variety of edge colors. Can anyone suggest where I am going wrong? What am I missing?