Combine flour, sugar and baking powder into a mixing bowl. Cut butter or shortening into dry mixture until it resembles coarse cornmeal. Make a well in the flour mixture. With a fork, beat together eggs, vanilla, orange juice and orange extract until well blended. Pour mixture into flour well and knead 5 minutes until smooth. Divide dough into two parts. Into one part, add 10 drops of green food coloring. Add 10 drops of red food coloring to the other dough, mixing each well to blend in colors. Pinch off a piece of the green dough about the size of an egg. Roll out to 12 inches long, and about as thick as your finger. Repeat with both doughs until all is used up. Place one roll of red dough and one roll of green dough close together on a cookie sheet. Repeat with double rolls (1 red and 1 green) 2 inches apart. Dough will rise when it bakes. Bake at 325 degrees for 10 minutes. Remove from oven and cool slightly. While still warm, pour glaze on and, if desired, finely chopped nuts. Cut into 1 inch slices.
Glaze: Combine 3 cups confectionary sugar, 3 tablespoons melted butter, 1 tablespoon Grand Marnier liquer, and 3 tablespoons boiling water.