If you mean the way the land is colored, then you can use the extension CLF Color by Z by Chris Fullmer - CLF extension
How can I write a ruby code editor without using an extension
can you use descriptive subjects, tia.
An extension is just a ruby script with some extra code to let you switch its loading on/off.
Get the CLF ColorByZ and look at its main code RB file within the subfolder.
From that you can get ideas on how to form your own toolset…
To explain it simply…
Collect all of the faces in your selection.
Find each face’s bounds.center.z
Assign it a material color based on that Z value.
e.g. set up a simple test of the face Z ‘range’ [>0 && <1 etc] and assign a color of your choosing…