Highlighting Subsystems and Blocks That Have Requirements
You can highlight subsystems and blocks that have requirements in a Simulink model:
In the Navigator, select Highlight Blocks that have Requirements from the View menu, or click the button. The menu item becomes checked.
In the Simulink model, the subsystems and blocks that have requirements associated with them appear highlighted in blue.
The highlight feature operates as a toggle switch. To turn off the highlighting, select Highlight Blocks that have Requirements from the View menu; the menu item is no longer checked. Or click the toolbar button.
The blocks and subsystems in the model are no longer highlighted.
Note
When you save a Simulink model, it is saved with the highlighting. You cannot later turn off the highlighting without opening the model again in the Navigator. Therefore, unless you want the highlighting to become a "permanent" part of the model file, turn off highlighting using the Navigator before you save a model file in Simulink.