Selection Highlight and Element Information Highlight

Selection highlights are shown on the contour and/or surface of selected elements.
Element information highlights are used to assist in selection (pre-selection highlight) and identifying related elements e.g. for labels and dimensions (related elements highlight).
All these highlights can be configured in Options > Work Environment > Selection and Element Information, or you can turn off selection highlights altogether.
Note: Surface highlights in 3D are available only when using the OpenGL 3D engine.
Note: If the Arrow tool is active, the highlight appears on its own, without your having to press Shift.
The related elements highlight also works with the Parameter transfer functions (Pick Up Parameters and Inject Parameters commands): the information highlight appears along with the eyedropper/syringe cursors right before you complete the parameter transfer. You do not need to press Shift to see the related elements highlight when using the Parameter Transfer function.