It can be handy to quickly view a 3D to even understand what it's depicting.
But sometimes a wireframe view can reveal some pretty important info about the model's complexity, how performant it would be e.g. in a VR headset, as an example. You can also see its internal structure to understand if you can even work with the file in the first place.

Click the view dropdown in the bottom middle of the 3D viewer and choose Wireframe.

The viewer will show the wireframe version of the 3D model, and as you can see in the example above, each wire inherits the color of the material in the full material preview. That should help keep things separated.
To get started, head to the free 3d viewer.