Need Help ----German Sw Africa Color

Need to find out a shade/ color not listed in Scott's .
On the stamps of German Southwest Africa ,they show a color of Olive Brown on the hyphenated 1897 issues ,it is listed as Scott 1b but they don't have a 1899 shade of olive brown .

Question is does any of the other catalogs carry a olive brown for the non-hyphenated 1899 issue ?

Shades…..I think the dark Brown block has forged overprints .

Looks like Scott 7 (front) and 7b (back).

PostmasterGS ---Your opinion is that it is a shade of Dark Brown not Olive Brown , ok .

Perf12 ---I can assure you those stamps are from Bernard {Bud } A. Hennig collection . There is not a expert in German that would question his judgement , matter in fact he trained most of those experts and established the expertization organization in Germany[He is the guy who taught German Philatelist expertizing at stamp shows in Germany in the 1960's and 1970's } ,he is considered the Judges judge . Bud put up his stock with Richard Drews Auctions [Again Richard Drews is America's Judge of Philatelic Judges ], So the stamps are beyond question at this point .

The block of 8 looks like Michel 5b, hellockerbraun; the block of 4 Michel 5a, dunkelockerbraun. The overprints were typographed. Often you can see the impression of the letters (not ink) of the overprint on the back of the stamps. Overprint looks good from the front.