The object is connected to a digital signal in the database. If the value is 1, the object
is drawn with the normal fill color, if the value is 0, it is drawn with DigLowColor.Color
which is stated in the object editor.
Compare to DigColor below, that set the specified color when the signal is high instead of low.
If to use DigLowColor or DigColor is a question how the component is to be drawn in the editor:
The way is will appear when the signal is high or low, i.e. if you want to draw the graph
as it will look when the plant is running or stopped.