Terrain motion measurement

Dear all,
As I want to see some displacement on earth, I think I must use Terrain motion measurement: Differential Interferometry.
If you go to the InSAR Principles: Guidelines for SAR Interferometry Processing and Interpretation, you can see below picture. As I can understand in this picture, if we want to know about terrain displacement, we must care about colour areas, not black area(i mean we should not care about DEM because it is something about elevation changes, not displacement) .
My question is:
How can I distinguish displacement with these colorful fringes?
I think when we have displacement, we have different colors, am I right?
What is difference between same colors like white, red and others?

Hello, marjanmarbouti. In DInSAR principle, every circle of fringe means 2*pi phase shift thus a displacement of half of wavelength( with respect to sentinel-1, it is about 2.8cm because sentinel-1 uses C-band).
The black holes might means failure in unwrapping process resulting from abrupt topographic change or coherence is not sufficient enough.
color itself represents phase change but specific color means nothing, you can change to any colorbar if you want although SAR community prefer rainbow-bar
I am a newbie here as well and hope it helps.