Interaction of Color

I'm currently reading Josef Alber's Interaction of Color and it's interesting that he used paper in his color experiments, so that the work would be consistent and that he could work solely with color, maintaining a controlled and balanced environment in terms of light and hue. Some of the works are very strong, while others more static and solid. It would be great to see these on a large scale like Motherwell or Rothko paintings. I get stuck on the perfection of most of them, as if he's lost the human aspect of error. While some, like the one below, has color diversity, darkness, light, error in irregularity and interesting forms emerging.