click to enlarge, or see it on Flickr
Shutter Speed: 1/8
When I first took the photo, I wasn't thinking with post-processing in mind, which actually led to some problems down the road. I wanted to increase the "cold" feel of the picture, so I shot with Tungsten white-balance. This added a lot of blue, but when I got it onto the computer, it looked kind of fake.
To get the effect, here are the steps I took in Photoshop.
1. Duplicate background layer.
2. B&W second layer with a Channel Mixer mask layer.
3. Put a Solid Color mask layer over at whatever opacity I used. I picked a dark green olive-ish color.
4. Flatten that out so I'm down to two layers again (1 original untouched image, 1 green monochrome).
5. Added a texture to my green monochrome image. It's super subtle. I think I only used 10% opacity.
6. Used the Levels box to remove some of the blue from my background layer. I took out enough that it probably posterized pretty badly, but that was taken care of in the next step.
7. Changed the blending mode on my green monochrome layer to Hue, played with opacity until the colors (olive green and cold blue) mixed to produce the color you see in the image.
8. Flattened, added a vignette.
This technique is really really fluid in that you can play with blending styles, colors, levels, opacity, or even paint-mask out parts of the colors if you want. I didn't even touch the Brightness/Contrast box after the final image was done, though in hindsight, I probably should have.
If you're crazy enough to try this technique (or a similar one), post a link in the comments. I'd love to see your results.