Displaying elevation data

[Vishal Nagpal]

I am trying to display elevation data dt1 and dt2 files.

I am getting a gray scale image as output. Though it gives an impression of
varying heights but
Is it possible to do more with it, like see contours, or see 3D.
I have tried changing scale but it only varies the shades of grey. 
Surprisingly A combine layer of tif and elevation shows some color shades. I
don't know why?
Vishal