The interrelationships among spatial distribution in the red, green, and blue channels of texture images of differently woven textile fabrics are investigated. A computational model for color mapping is developed based on the channel proportionality found in the investigation. The computational model developed has two modes: gray-to-color mapping (GCM) and color-to-color mapping (CCM) that deal with different images. For the GCM mode, the spatial distribution of luminance is known. The algorithm needs to deduce data in three channels for a color image from 1-D spatial distribution of luminance. Whereas in the CCM mode, the information for each of the three channels is known. Numerical and psychophysical experiments are carried out to evaluate the accuracy of the color mapping algorithm quantitatively. Satisfactory color accuracy of the mapped images was obtained according to the results of both numerical calculation and visual experiment.