Preheat oven to 350 degrees. Beat eggs; add sugar. Mix cocoa and food coloring. Add butter and egg mixture; mix well. Sift together flour and salt. Add to creamed mixture alternately with buttermilk. Blend in vanilla. In a small bowl, combine soda and vinegar and add to mixture. Pour into three 8-inch round greased and floured pans. Bake for 20 to 25 minutes, or until tests done.
Blend cream cheese and butter. Add marshmallows and sugar and blend. Fold in coconut and nuts. Spread between layers and on top and sides of cooled cake.