When a line is drawn, the number of colors that can be displayed at once for that line is:
This difference in drawn colors applies only to lines not to filled regions. If a brush object is selected and visible foreground and background colors are chosen, a two-color pattern is drawn when an area is filled using the brush.
The OS/2 version of CreatePolygonRgn matches the Windows NT behavior for brush objects. However, if a pen object is selected, the OS/2 version draws only one color, no matter what pen style or background mix are chosen. Any gaps in the pattern, as determined by the pen style, will be the color of the region on which the line is drawn. This behavior differs from the Windows NT behavior due to an OS/2 GPI restriction.