The theory behind contrast is simple enough: juxtapose two disparate or opposing ideas and they can enhance or offset each other. This is true of non-visual mediums too; comedy heightens tragedy, musical harmony is more dramatic when resolved from dissonance. A simple concept, however, does not mean easy execution. In my exploration, I discovered that, for me, some restraint is needed for appropriate use of contrast.
In the first image, the eye is drawn to the pink hair. Very simply, that neon colour looks like it's been drawn from a completely different palette to the rest of the poster. Using a contrasting colour to highlight the subject of a piece is so effective here that it need only take up very little space.
The second image uses a very clever contrast in line work. The person is very cleanly outlined, whereas the lines of the waves have more energy, reflecting the chaos they represent.
It turns out that I'm a sucker for clever use of negative space:
When the negative space is a meaningful shape or figure, as in the Skyrim poster, it can really add to the character of a piece. Check out Levente Szabo's amazing film posters for great examples.
I love the little house with its chimney smoke. It's as if the background and the smoke have swapped places, which leaves a lot more space around the house, making it seem smaller and more isolated.
These three illustrations all use tiny figures to accentuate the vastness of their surroundings. Again, it's an obvious technique, but well executed in these instances. The length of the railway arches makes the figure's fall seem to last forever, and the length of the spaceman's shadow gives greater power to the daunting spacescape (not sure if that's a word, but I like it).
I'd not realised it about myself before starting this little exploratory journey, but I'm drawn to monotone palettes with clever use of value. The Metropolis poster is particularly dramatic I think. The artist has managed to use value to describe texture and mood brilliantly, I think.