Preheat oven to 350 degrees. Generously coat 12-cup bundt pan with cooking spray. Combine flour, baking powder, salt and soda; reserve. On mediium-high speed, beat egg substitute, granulated sugar, oil, yogurt and 1/2 cup lemon juice until combined. Beat in food coloring. On medium -low speed, gradually beat in flour mixture. Stir in zest. Pour into pan. Bake 45 minutes or until toothpick inserted into center comes out clean. Cool 20 minutes. Remove from pan to rack; ccol completely. Whisk together confectioners' sugar and remaining 3 Tbsp lemon juice until smooth; pour over cake. If desired, garnish with lemon slices.