Hi,
The chart doesn't provide a built-in series that can fill arbitrary polygons. With the Line series you can stroke a polygon but you cannot fill it. The High-Low series gets close to your requirement - it fills the area enclosed between two poly-lines (that have the same X values). You can check if the regions that you have to paint can be represented by this series.
If not - the options that remain are to use either custom painting or the custom series. You can take a look at the following examples in our WinForms application:
All Examples > Custom Painting > Custom Painting Using GDI+
All Examples > Custom Painting > Painting in Overlay
All Examples > Custom Painting > Custom Series
Best Regards,
Nevron Support Team