Shepard Fairey

Shepard Fairey 

Here he uses the values to make his face stand out. and i think he uses white on his face in a ironic way because Obama was our first black president.

In this picture the face stands out because of the values

In his design the dominant element of design is value, he uses these to transmit the his messaged, often the shapes aren't designed as well, but he focuses a lot with the value, for his stickers that look a lot like stencils he uses only value, or almost only value 
All his work has a meaning, in these three examples he uses Obama as a symbol of progress, he was the first black president, he was the one that help america in the crisis he is the progression of the state