Here is my node system, I'll explain it deeper in the silhouette tutorial:
Pull your mouse over to see it before, and after compositing!
1. - The picture I've rendered was Black&White, I was curious if I can color it with in the compositor... Well, I can :)
2. - The picture was too flat, so I made a marble texture, blurred it, and mixed it with overlay to the picture, so it became a little "smoky", which makes it a little more intense.
3. - This is the coloring part: I made a color blend texture, blend type was diagonal, and this kinda exciting gradient was born (I wanted the inside of the warehouse deep blue, and kinda orange for the door, where the light and the spy comes from, and a strange from cold-to-warm gradient became.)
4. - I made the image brighter (I couldn't read the text)
5. - It's just a little glow, the black character and the bright light was awful without glow.
6. - It's just a vignette, I needed 4 nodes to generate it, more about it later :)
7. - I've put my logo to the bottom right of the final image, I wrote below the nodes what they did.
Here I'm just mixing them into one image :)
If you have any question, don't be afraid to ask, I'll help you if I can :)