Various attempts have been made to overcome the mathematical problems of CIECAM02. All focused on modifications keeping the original structure of CIECAM02, and resulted in some loss of accuracy in predicting experimental visual results. The current paper proposes to merge the separate adaptation to the chromaticity and luminance of the illuminant by using a new space rather than the two different spaces proposed in the original CIECAM02. The new space, defined by a new matrix M16, is a cone-like space. From the new structure and space a new colour appearance model, named CAM16, has been derived. At the same time, a new chromatic adaptation transform, named CAT16, and a new uniform colour space, named CAM16-UCS, have been also developed. Performance tests showed that CAM16 and its associated CAT16 and CAM16-UCS not only solved all the mathematical problems reported for CIECAM02, but also performed as well as or even better than the original CIECAM02 model and its associated chromatic adaptation transform CAT02 and color space CAM02-UCS. These performance tests included predictions of experimental data currently available as visual colour appearance datasets, corresponding colour datasets and colour difference datasets. Furthermore, CAM16 is simpler than CIECAM02.