Comment 1 for bug 572559

OK, there a number of problems here:

1. tkplot does not support different label colors. In your example they are the same color, but the color is set for each vertex individually, and this is not supported. A workaround is to give the label color in the plot() call, or to set the default with igraph.par().

2. NA as frame color is not supported, either. Supply the same color here as for the vertices, to get rid of the frame.

3. label.cex cannot be different for different vertices, either. The same problem as for 'label.color'.

I will fix these, i.e. add support for them in the next version. Thanks for the report!

After running
i96e <- remove.vertex.attribute(i96e, "label.color")
i96e <- remove.vertex.attribute(i96e, "frame.color")
i96e <- remove.vertex.attribute(i96e, "label.cex")
tkplot() works, although it is quite slow.