To make simple graphics easier, ProXL associates a default graphics context with each drawable. Thus you may omit the GC argument to all the drawing primitives, in which case the destination drawable's default GC is used. Alternatively, you may specify a GC in drawing primitives and ignore the default GC. You may also replace a drawable's default GC at any time.
The concept of a drawable's GC allows you to forget about GCs as separate entities, and instead think of drawables as having graphics attributes. ProXL manages this for you. So if you want to draw in a window in green, you can set the window's foreground to green, and then draw. You needn't worry about GCs at all.