Hi, sorry for the late reply, we had national day here and had to celebrate a bit 
I sent you the file to see if you had problems with the display engine, you hardware or the display modes, and since you got basically the same image as I did we can rule that out.
Rhino 6 and 7 has a different rendered mode than Rhino 5 as it supports environment lighting, causing the âarctic lookâ and since the default material in Rhino, that is applied to the default layers and thus the object on those layers (since objects have âmaterial by layerâ as default setting) you will get that all-white look when you switch to rendered display mode.
To sum that up: Default in V7 is white ojbjects in a soft lit white environment.
So whatâs left is then to show you how this is done 
In the file I sent you I made three spheres and did the following:
1- default material on sphere one, nothing done
2- a basic plastic material is made and applied to sphere two where the color is changed to red and the reflections are dulled a bit, and
3- a metal material is made and applied to sphere three with the color set to âgoldâ
4- I then created a âcustomâ environment by importing one from Rhinos library to light the scene and give reflections
5- Sun is turned on to give a directional light that casts shadows
You can type MATERIALS to open the material dialogbox and see the materials in the file, add new ones or import default ones from Rhinoâs library.
You can type ENVIRONMENTS to open the environment tab and
you can type SUN to set the sun to a given time for a given location or adjust the hight and rotation manually.
(And you can add lights, like a directional light (like the sun, but free standing) or a rectangular light to cast soft shadows, or a spotligth. All of these lights can have different colors and strengths)
You can look at these tutorials on rendering to learn more.
I made a new file for you to investigate.
Here rectangular lights with different shapes, colors and intensities are used, and the environment is reduced to prevent overlighting, and then RAYTRACED mode is used to render the scene with reflections and shadows. The rendered view for this scene doesnât look good since environment is reduced, but thatâs just how Rhino is since it doesnât use advanced realtime features like screenspacereflection or cubemapping etc.
Raytraced:
OpenGL:
(The car is not made by me, itâs just a simple mesh model downloaded years ago that I use for size when working on projects) ((Here is one I made: WIP SubD Dino 246 - #37 by Holo)
CAR in studio.3dm (1.6 MB)