Color
This picture is showing an analogous color scheme, which is when colors that are next to each other on the color wheel are present. The yellow tinted veggies with the green veggies show the two colors that are near each other.
This picture shows a complementary color scheme. This is when colors that are across from each other on the color wheel are used to to show the main focus. The blue on the bags is used to make the oranges pop in this picture.