Every new shape I draw in the Pencil tool always comes up as transparent, where as other tools (rectangle, ellipse, polygon, etc.) always keep their default or previously chosen fill color. Although thankfully I just have to press D to fill in the default color, it quickly becomes a hassle to remember when I'm rapidly building shape and sometimes disrupts my workflow. Isn't there a way to just keep its default color, like how the other shape tools behave?
Double click the pencil tool in the toolbar to bring up the pencil tool options.
Tick the box to "Fill New Pencil Strokes". Then choose your fill color and your new Pencil strokes will be filled.
As you will see this is fine if you are drawing closed paths but becomes a bit strange if you are drawing open paths. Hence the option to have them not filled.