Mix and bake chocolate cake mix according to box directions. Cool & flip out both. Wrap 1 chocolate layer and freeze for later use.
Mix white cake according to box directions. Divide batter in half. Add several drops of red food coloring to the first half and mix; pour in cake pan. Add green food coloring to the other half of the batter and stir; pour in cake pan. Bake, cool, and pop out. Stack the chocolate layer first and frost with white frosting. Add the red layer next, frost, and finish with the green layer. Frost whole cake with white frosting.
Decorate with plastic decorations or red and yellow piping gel, adding a gold star on top (representing the Star of Bethlehem) and the red candle in the center.
Light the red candle and read the Christmas story. Light each person's small candles from Jesus' candle and carefully add them to the cake. Sing Happy Birthday to Jesus.