SO I have been working on the Gold Challenge. I started with looking into the Apple Documentation for CALayer Shadow properties. The documentation states that if the layer is not transparent and has a background color then the shadow will not show through the layer. However, this does not appear tp be the case. We have a background color and the layer is not transparent, alpha > 0.0. From the documentation
The left and middle versions include a background color so the shadow appears only around the border of the layer.