strict digraph
{
    a -> b[ colorscheme=x11      fontcolor=red        labelfontcolor=blue      label="label" taillabel="tail" headlabel="head" ];
    c -> d[ colorscheme=svg      fontcolor=blueviolet labelfontcolor=limegreen label="label" taillabel="tail" headlabel="head" ];
    e -> f[ colorscheme=paired12 fontcolor=2          labelfontcolor=10        label="label" taillabel="tail" headlabel="head" ];

    a [ label="colorscheme=x11" ];
    b [ label="colorscheme=x11" ];

    c [ label="colorscheme=svg" ];
    d [ label="colorscheme=svg" ];
    
    e [ label="colorscheme=paired12" ];
    f [ label="colorscheme=paired12" ];
}
