You may be wondering what all those colors mean when you look at your Slab Layout. When you layout your slab pieces in Step 5, you may see a variety of different colors. Each of these is telling you something about the way the piece fits on the slab.
The most important thing is to remember that green means you are good to go! When the pieces turn green that means they are placed on the slab and not touching or overlapping.
When you first open your Slab Layout, all the pieces will be stacked on top of each other and slightly off the slab. The color warnings prevent smaller pieces from accidentally getting lost under larger pieces.