EXFO FTB-800 Series for FTB-1 - Manual (Page 47)

Graphical User Interface Overview
NetBlazer 37
Keyboard Usage
For multiplexing keyboard, tap on all mapped signals that have to be
added/removed to/from the test path.
A mapped signal with an orange background color is part of the test
path.
A mapped signal with a gray background color is not part of the test
path.