question about results of optimiser.

 
you know that if more than two parameters are used,a graph of 2D surface cannot show all the results.
then what's the color for?
is it the best result filling the blank?
hope you understand my question.
sorry for my bad english.
thank you guys.
 
Put cursor over and you will see pop up tip.
 
if i use three parameters, it should be 3D SPACE.
(x,y,z), if i keep x,y and different z make different result, but shown by a 2d surface,there is only one blank to fill.
 
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