Click on the Options menu item
to display the Options dialog box.
You can choose whether or not colours corresponding to heights are displayed, and if so, whether black lines on the white map background are displayed as in the original, or if they are converted to white outside the area of a transformed image or on a map which has no transformed image on it.
You can also shift the colour spectrum by clicking on the spin buttons to expand or contract the spectral pattern. If an image is not open, all heights will show as zero.
Clicking on the default button will restore the full spectral range, turn colouring on and set map lines outside a transformed image to black.
For changed options to take effect, close the current image if one is displayed and open it again. Changes made are also recorded so that the options are the same the next time the programme starts. If there is no image loaded, changes in the options will be applied immediately as soon as one is.