RoomShaker
Tutorial:
Understanding
The Tile Indicator Bars
This Tutorial assumes that RoomShaker is setup correctly on your system See Tutorials: Setting up RoomShaker & POPLM.
In this tutorial I will cover the use of the thin bars that surround the room editor. These bars are known as the Adjacent Room Indicator Bars, the bars change colours to indicate the tiles on the corresponding edge of the adjacent room (if any).
These bars can help you line up tiles when matching
the geometry between rooms. The bars may be toggled on or off in the View
menu.
RoomShaker will automatically remove a bar if there is no room connected to
the corresponding edge.
In the image below I have an empty room.

Using the indicators we can see that the room
to the left has a Wall, Empty, Floor along
the very right-side edge and that the room to the right has 2 Walls
with an exit through the middle with Spikes along its left-side
edge.
We can also see that the room above has a ledge with Pillars
& Floor and there is no room below.
By reading the tile indicator bars I was able to create the room below to fit the surrounding rooms without having to move to any other rooms and check it's tiles. This helps speed up the editing process quiet a lot.

Now, you might be asking How do I know what the colours mean?. Well RoomShaker can tell you the colour code of the indicator bars.
Go to the View menu and select Indicator Legend this will present the Indicator Colour-code. Also, the colour-code legend can be found in RoomShaker help under Room Editing -> Adjacent Room Indicators -> Adjacent Room Indicator colour-code legend.