Set here the visual aspect of a plane.
r, g, b
The 
r, 
g, 
b entries define the plane color,
from black (0.0, 0.0, 0.0) to white (1.0, 1.0, 1.0).
Scale
When the plane is linked in 
Independent mode, the 
Scale
factor can be used to change the plane size, including its child objects.
Plane objects are scaled around the plane center.
When the plane is linked in 
Automatic mode, only its parent
object can be scaled (thus changing the size of all its child objects,
including the plane), and the 
Scale entry is disabled.
The visual representation of an object is always 
scaled by its own scale factor multiplied by the scale factor
of all its parent objects until layer, inclusive.