Dissolve lemon gelatin in 1-1/4 cups boiling water; cool slightly. Combine sour cream, mayonnaise, sugar, and lemon juice. Blend mixture into lemon gelatin. Chill until slightly thickened, about 1 hour - and fold in apples and pecans.
Meanwhile, dissolve orange gelatin in 1 cup boiling water. Add apple juice. Pour 2/3 cup of liquid into a 6-cup ring mold. Chill until set but not firm, about 30 minutes. Chill remaining orange gelatin mixture until slightly thickened.
Spoon lemon gelatin mixture over orange gelatin in mold and top with remaining orange gelatin. Chill until firm - at least 4 hours but overnight if possible to insure a very firm salad and one that will unmold easily.