Visualization Modes for Sketcher Elements
Three visualization modes are available for sketcher elements: Usual mode, Low Light and No 3D Background.
Usual
The Usual mode 
is the default option. When activated, the 3D
geometry is visible in the Sketcher.
Low Light
If activated, the Low Light mode 
introduces a low light for all geometrical elements
and features that then appear as gray-colored, except for the
current sketch. Additionally, although you can see them, you cannot
select them. You can just handle Sketcher elements.
No 3D Background
If activated, the No 3D Background mode 
hides all geometrical elements and features
(products, 3D shapes, etc.) except for the current sketch. Even if
geometrical elements are coplanar with the sketch plane, these
elements are hidden.
shows all geometric elements outside the sketch
plane with a standard intensity, but these elements cannot be
picked.
shows all geometric elements outside the sketch
plane with a low intensity. These elements can be picked.
locks the current view point is (provided a
visualization mode is set).