This paper reviews the color image processing techniques used in the printing industry for the color space transformation. Generally, the techniques can be classified as the color mixing models, multiple regression, 3D lookup table (LUT) with interpolation, neural network, and fuzzy logic. The following techniques are briefly discussed. (1) Color mixing models such as the Neugebauer equations, Yule-Nielsen model, Clapper-Yule model, Beer-Bouguer law, and Kubelka-Munk theory. (2) Multiple regression. (3) 3D LUT with four geometric interpolations - trilinear, prism, pyramid, and tetrahedral. (4) Artificial neural networks of the multilayer feed-forward and cascade correlation nets. (5) Fuzzy logic. These techniques are compared, whenever possible, with respect to the accuracy, memory requirement, speed, and computational cost.