Fill-Color2
This property, used in conjunction with the Fill-Percent property, defines the color used to fill the portion of frame not filled with the color set in the Fill-Color property, when the value of the Fill-Percent property is less than 100. The default value, zero, indicates that no color must be applied to that frame portion. See "Color management" for further details.
 
Example - Define a frame control with 2 fill colors, white and gray, the fill-percent tells the percentage for the first fill color and the rest is for the other fill color
screen section.
...
  03 screen-1-fr-1 Frame
     line 17.7
     column 20.0
     size 24.3 cells 
     lines 27.8 cells 
     id 16
     fill-color 16
     fill-color2 9
     fill-percent 73
     .