Colorize edges of one or more graph layouts (that already have layout information) to clarify crossing edges
edgepaint {{path/to/layout1.gv}} {{path/to/layout2.gv ...}} > {{path/to/output.gv}}
edgepaint {{path/to/layout1.gv}} {{path/to/layout2.gv ...}} > {{path/to/output.gv}}