Select the Color from the drop down list of 254 pens. To set a custom color, select {custom} and click on the color swatch.
Select the Line type from the drop down list. The line types listed are those currently available in your CAD system. If you wish to add a line type, cancel this dialog and create the line type in your host CAD system.
Select the Line weight from the drop down list. Note that line weights are real world dimensions so if you select a line weight of 2mm, the object will be drawn with 2mm thick lines.