This script do a quickly get user back to root level(level 0) of the model and select none. It will save a lot of clicks or Esc key pressing when you are working in deep levels.
A small plugin, give a "Toggle Display Color By Layer"'s button and also add a command to menu Extensions so you can create a shortcut for this feature.
Normalize Linear Dimensions of a SketchUp LayOut File with selective options.