Block Chromatics Germany

Don't know much about this set, other than browsing a little online it appears they are rather sought after. These were purchased at a local estate sell several years ago and were unused, they've been sitting in back of a cupboard unused since then. There is a set of 6 plates and bowls, 4 cups, and a couple other platters/bowls. Each piece is labeled on bottom with Block Chromatics Germeny and a 4000 series number, except for 1 bowl platter which says Arzberg Chromatics. Would be curious if anyone knows any details on these and what makes them so sought after, they really are a neat and do seem ahead of their time!