That's not always the case; I have worked with trim panels that have involved removing a face plate of a radio, and loosen the function panels (like the heater controls, etc.) The control panels angle through the opening, on the radio the faceplate covered the edges without removing the unit.I know the door and dash panels are displayed to show where they go. I know the red sections are the colored panels under discussion. I know the dash does not have to be removed to get the optional panels.
I am talking about the ease of installation of the colored panels on the dash. Usually, components (like stereos) have fascias slightly larger than the unit so it overlaps the hole, covering the surrounding part of the panel in which it is installed. This gives it a nice clean look. That is the usual technique. If that technique is used here, it would require removing the unit, installing the panel, then reinstalling the unit. They may do this. It seems more labor intensive than what I believe they want the marshaling center work to be.
There are also head units (aka radio) that you slide a special tool down both side to unlock it, and it will slide out, no wires attached. There is a case that is mounted with a hot plug at the back, so the head unit plugs in when you slide it back in. Doing a trim on that is really easy.
The panels are most likely attached with either metal or plastic clips.