Here are some pictures. The first three are the 1957 experimental types:
Here are the two variants of BGS cloth. The first is the 1957-1963 type, the second picture is for items made in 1967-1975 *and* used for the 1959-1963 Zeltbahn.
The colors vary from item to item, especially with use, but here are some general rules:
1. The earlier type is lighter and found on a coarser material.
2. The later type often has a very deep olive color to it. Cloth is always smooth)
3. The earlier type has almost no space between the red and green shapes, the later type always has space between the two shapes.
Here is a picture of Berlin Polizei Sumpftarn. It is easy to distinguish when you know what to look for, but to most there is no difference:
The colors appear more "washed out" and the rain strokes are very light colored compared to either of the BGS patterns. The uniform is based on the BGS 1958-1963 type, but there are some construction differences and the materials used are not the same.