Juxtaposition in Modern Art

Juxtaposition is the contrast of two colors put beside each other in an art piece a good example of this is in these two paintings done by Sammy Slabbnick ("Uptown Girl" and "The Discovery of Modern Art") 
http://img2.archilovers.com/story/efce859338064e77b7bd93341900b4c7.jpg
These paintings show juxtaposition through the contrast between older style (black and white) photos and more modern (coloured) pictures.The juxtaposition is even more evident as the old and new photos are directly placed upon each other making it easier to see the comparison between the old and the new.