This is the only option in the Display tab and is only needed if you are using the Avoid Objects function (with its own tab).
It is enabled, by default, and can be disabled by unchecking the box.
If you are using an object in your scene that you are controlling in the Avoid Objects tab, you will make it invisible by disabling this option.
Avoid Objects enabled, with tfRock as a wireframe.
Avoid Objects is disabled, making the object invisible in the viewport.
The wireframe color can be altered using the color picker.
Wireframe color changed, from the default pink, to blue.