Electronic skins have attracted significant research interest in the biomedical engineering field including wearable devices, artificial prostheses, software robots, and so on. However, the integration of electronic skin for use in rehabilitation exercise remains unexplored. Here, we propose a novel, conductive structurally colored composite hydrogel for use as a robotic knuckle rehabilitation skin. It was found that the composite structure has an obvious color variation and electromechanical properties during the bending process. Therefore, this film could be used as a multi-signal response electronic skin to achieve real-time color sensing and electrical response, as well as for the human knuckle rehabilitation robot. These results indicated that the structurally colored composite hydrogels are valuable for use in many practical biomedical rehabilitation exercises where they are used as an electronic skin to give real-time color sensing and electrical response, and as well can be used in a human knuckle rehabilitation robot.