Awesome, i just gave it a try with really no effort and the result is rather impressive
was looking for some lineart to test, decided to use this one :
http://media.wizards.com/images/magic/d ... 4_4_lg.jpg( from
that page )
loaded the image and added a new layer on top , on which i would just do the brush strokes

Just put some colors strokes to set where i wanted the area to recieve the coloring

Using G'MIC colorize (comics) , then setting the transformed layer to Multiply :

Rather amazing what this tool can do with nearly no effort ! I'm really impressed.