Principles of Elements

Value. 

This shows value by seeing the difference between dark and light. The surfers are very dark and the ocean and sky are very bright. 

Unity.

This shows unity by how the car is orange and so are the two stripes on the pole next to it. The color orange unifies the picture all together and by being orange the picture becomes one.

Emphasis.

This shows emphasis by how the blue is on the black. The blue stands out because the ground is so black. Emphasis is something where the color stands out. In this picture i believe the blue stands out very much.

Movement.

This shows movement by how the football players are tackling each other. They are in mid-motion and this shows movement because they are physically moving.