[Nauty] Can we do colored edges in nauty?

[Wutnipong Sompamitr]

Hello,

I am very new to nauty. I have a research that needs to use graph
isomorphism.  However, the problem I am working on directed multigraph
with labeled (colored) edges.

Does nauty handle this or are there any way to do such thing without
adding more colored vertices to the graph (that slows nauty, right?)?

BTW, I browsed many old messages, but couldn't find an example of how to
define to color of vertex.  Any hint would be great.  Thank you.

-Wutnipong