With the explosive development of communication technology, digital images are more widely stored and transmitted on the network as a medium of communication among people. At the same time, the security of the digital image has become the focus of people's attention, and it is also the hotspot and difficulty of current research. Therefore, a novel color image encryption scheme is proposed in this paper by combining the 6-dimensional cellular neural network (CNN) and Chen's hyperchaotic system. In the proposed scheme, the initial keys and switching function generated by the plaintext image are utilized to control the CNN to complete the scrambling operation. Then, using the Chen's hyperchaotic system to diffuse the scrambled image for realizing higher security. Finally, the simulation tests and security performance analyses on the proposed encryption scheme are carried out. Experimental results demonstrate that the proposed scheme has an excellent encryption effect compared with other advanced image cryptography systems.