Prepare the Apples: Slice both the red and green apples into matchstick pieces. Place them in a bowl, pour the lemon juice over the apple pieces, and toss well to coat. Let the apples sit for about 5 minutes to absorb the lemon juice, which prevents browning.

Combine Ingredients: In a large mixing bowl, add the matchstick carrots, diced onion, and dried cranberries.

Add the Apples: After the apples have soaked in lemon juice, add them to the mixing bowl with the other ingredients.

Make the Dressing: Add the vanilla yogurt, mayonnaise, sugar, salt, and black pepper to the bowl. Stir everything together until well combined and evenly coated.

Finish with Mandarins: Gently fold in the drained mandarin segments to avoid breaking them up too much.

Chill: Cover the bowl and refrigerate for at least 3 hours before serving to let the flavors meld.