Color.Gradient (gb.image)
Static Function Gradient ( Color1 As Integer, Color2 As Integer [ , Weight As Float ] ) As Integer
Return a color that is the RGB mean between 
Color1 and 
Color2
Weight is the relative weight of the 
Color2 color:
  - 
If Weight is 
0, then Color1 is returned.
 
  - 
If Weight is 
1, then Color2 is returned.
 
  - 
Otherwise an intermediate color is returned.
 
  
If 
Weight is not specified, its value is 
0.5.