Hiding and displaying the solder mask
The solder mask is normally not visible in the PCB/Footprint view. However you can show/hide the mask by checking the 
in the solder mask properties in the layers panel.
The Layers panel
A TPH pad on the left connected to a SMT pad on the right
Show pads as yellow. SMT pads have yellow border
Solder mask visible. Color gray with semi-transparency
Outline mask holes checked. Yellow outline for cutouts
Show PCB filled