En el link:
http://davidlynch.org/projects/maphi...mo_simple.html
Llenas el fondo con un color por ejemplo:
Código HTML:
Ver original<area href="#" shape="poly" coords="219,190,225,175,237,157,239,148,245,142,251,140,263,140,265,139,310,139,311,145,364,182,363,201,343,221,333,213,329,181,313,177,330,234,295,231,292,174,279,176,282,204,269,220,255,206,267,167,235,193" alt="Legs" data-maphilight='{"stroke":false,"fillColor":"fff000","fillOpacity":1,"alwaysOn":true}' title="Metadata'd up a bit">
"fillColor":"fff000" es el color que deseas llenar el poligono.
Saludos