Strange Material on Surfaces in all Views

Hello, I purchased a 3D site model for one of my projects, it is an OBJ file. Every time I open the OBJ file with Rhino 6 the surfaces have this strange gradient. This gradient appears in all views like Shaded, Rendered, and Arctic. Since I am planning on rendering new views with my project I am hoping to resolve this weird reflection/gradient. This is how it appears in Arctic view.

Any suggestions will help!

Try selecting all meshes, then unwelding the meshes:

Copy and paste the next macro into the Rhino command-line

-_Unweld _ModifyNormals=_Yes 75 _Enter

This seems to have worked, thank you!!