The results are all over the map, but a few of the test images -- like the puppy and Monarch butterfly above -- look pretty good. The algorithms work using a few common sense rules (the sky is typically blue, dirt roads are usually brown and have a similar texture), and "hallucinating" a plausible colorized photo. But the results are far from perfect. For example, the neural net has a hard time coloring within the lines with more complex subjects like vegetables on a plate or keeping a heron bright white. When it does hit the mark, however, it's impressive. In fact, 20 percent of the folks surveyed for a "colorization Turing test" were fooled into thinking that the images weren't monochrome to start.