The color map used by the AR Sandbox is a simple text file (HeightColorMap.cpt in the SARndbox package’s etc/ directory). Each row defines one color. The first column in each row is the elevation in centimeters relative to the base plane defined during calibration, and the second to fourth columns are the color at that elevation in the RGB color model (0 0 0 is black, 255 255 255 is white, 255 0 0 is red, etc.).
Not from inside the AR Sandbox application itself, but you could modify the color map file externally, say through a set of scripts bound to keys via the desktop’s shortcut system, and from inside those scripts notify the AR Sandbox that the color map has been updated through the AR Sandbox application’s control pipe.