You typically assign a color map to an image at the time of insertion, but you can change the color map at any time, using the Image Manager toolspace.
Color maps apply primarily to digital elevation models (DEM) and multispectral images. AutoCAD Raster Design toolset automatically assigns color maps to traditional bitmaps, tagged image files (TIFF) and other displayed images at the time of insertion. When a DEM or multispectral image is inserted, AutoCAD Raster Design toolset displays the appropriate dialog for configuring a color map.
DEM files use a palette color map, which has multiple settings that are configured in the Palette Color Map Definition Dialog Box. Palette color maps can be saved for reuse with other files.
Multispectral files use a band assignment color map, which simply assigns data bands to color channels. This type of color map is not saved, as it is quite easy to configure in the process of image insertion.