using "diameter dimension" command to label circle's diameter

I have already created the center lines for a circle using the "center
mark" command using the color cyan on a particular layer.
However, I also need to use the "diameter dimension" command to show
the diameter of the circle in green. But how do I prevent it from
putting in a 2nd set of center lines? The number value should be
green and the center lines should be cyan. Thanks.