Use
If you want to highlight selected activities, operations or orders in the diagram section of the
detailed scheduling board , you can do so by using colors. The objects are allocated colors that are defined by SAP.Procedure
Select the operation or order, and choose Edit → Highlight in color.Result
The operation or order is highlighted in color. If you want to remove the highlights, choose Edit → Undo colored highlights.
You can select highlighted objects in order to execute a scheduling function on them (for example, Deallocate) by choosing Edit → Select.

You can also only