Shading
The Bar control consists of a number of rows defined with the Width property that make the Bar control thicker or thinner.
The color of each single row is defined by the Colors property. If not set, each row will be drawn with the color set in the Color or Foreground-Color properties.
To obtain a 3-D effect, some rows must be drawn with a lighter or a darker color. This property allows you to draw lighter or darker rows, changing their brightness instead of their color definition
Valid values are:
-2
Very dark, usually black.
-1
Darker than normal.
0
Unchanged.
1
Lighter than normal.
2
Very light, usually white.
Since this property can be set for each row, a list of values is needed in order to determine the brightness of each row.
When values are enclosed between parentheses, a new list is defined at once.
 
Example - A typical 3-D Bar control.
screen section.
...
  03 screen-1-br-2 Bar
     line 5.0
     column 12.0
     size 46.0 cells 
     id 2
     color white low
     width 2
     shading (-11)
     .