Hi FokkerJ,
I think you are looking at the darkest color in each. In #3 blue is the darkest color. Directly below the center tan polygons are blue-green polygons. This color is replaced with a much darker color in #6. The blue is also lighter in #6, but the same polygons are blue. There are some changes to each of the colors, with the biggest change to the blue-green, but the pattern has not changed.
Compare the NASM sample (1) with the Manfred Thiemeyer sample (2) on Mark Miller's
German 5 Color Lozenge Camouflage Scheme page. You will see a similar change.
Steve
My post appears a bit redundant, since aust3298 posted while I was writing.