This version represents only the blue channel of the original and has been completely de-saturated. This simulates the earliest film emulsions that were only blue sensitive. It is, however, not made monochrome - it is still a color image with red, green, and blue channels identical. The color balance of the image is then shifted warm (increase red, decrease blue) to simulate the warm toned prints of the time. Notice the contrast, the washed out sky and the very dark foliage. This is typical of prints of the 19th century. Later Ortho films added a green sensitizer to improve upon this.