Light Skinned refers to the color of your pie. Yellow sweet potatoes make a yellow or light skinned pie

My grandson Robert asked me what is the difference between yams and sweet potatoes.  I told him I make sweet potato pies out of yams.  Yams are orange in color and sweet potatoes are yellow.  For purposes of clarity, I made sweet potato pies for dinner tonight.  The sweet orange colored potatoes are yams which is simply one of the varieties of sweet potatoes.

1 pound of sweet potatoes, 3/4 cups salted butter, 1 cup white sugar, 1/4 cup light brown sugar, 1/2 cup condensed sweetened milk, 1/4  cup evaporated milk, 3 eggs, beaten, 1/2 teaspoon pumpkin pie spice, 1/2 teaspoon salt, 1/2 teaspoon ground mace, 1 teaspoon vanilla extract, 1 (9-inch) unbaked pie shell.

Put the potatoes in a large pan, cover with water and cook over medium heat for approximately 15-minutes or until the potatoes are tender.  Remove from the heat, peel and mash the potatoes with a hand mixer. Add the eggs, butter, sugar, spices, and cream together. Taste the mixture should be slightly sweeter than you want your pie to taste.  If not add more white sugar.  Pour into the pie shell and bake on the bottom rack at 350 degrees until the center is firm.  Allow the pie to cool then cut and serve.