strange steps in color scale

Hi all,
I have been having trouble with image plotting in igor. While the features come out nicely, there are strange steps in color. For clarity, I attach an image and a cut.
Does anyone know how to fix this?

thanks a lot,
Vishal
stepproblem.png (60.65 KB)
Some of the color tables (like Rainbow) have only 100 distinct colors in them. Others have more, like 256 (Rainbow256). Perhaps you need to choose a different color table.

--Jim Prouty
Software Engineer, WaveMetrics, Inc.