Looking at the gun scene, blueing and colour hardening were used as a rust barrier. These finishes could have been used for armour even earlier. All carbon steels of old would readily become matt/tarnished over the length of a campaign. Fashion allowed for darkened swords of all kinds.
Night attacks from any time would see equipment and faces blackened. So there is nothing really new to it. However, todays weapon systems are so effective and have such a reach, men and equipment have to be spread about far and wide and camouflage is the main protection. Troops located can be targeted. The Australian Army are issued brown/green boots which forms part of a complete comouflage package.
I think lessons learnt from the Crimea and American Civil War were finaly put into operation in the Boer War. Camoflage was used by both sides extensively, the most obvious being the British issue of Khaki. The beginnings of modern manoeuver warfare tactics.
Black blades has a lot to do with stainless steels remaining bright, unlike carbon steels that take a dull/blackened patena from bluing or just regular use.
tac45, the Webley revolvers were made matt or blued depending where they were bought. It was normal for gentlemen to arm themselves with pocket revolvers for protection from the riff raff. You could walk into a top London gentlemans outfitter and buy yourself not only your travel luggage but also a revover to go with it. The Army & Navy Store had mail order catalogues, big fat ones, for those anywhere in the Empire to shop from home.
Churchill had bought himself a very modern German Broom Handle Automatic Mauser pistol, which he put to good use against the "fuzzy wuzzies". Shop Webleys often have a more refined finish. But I'm now getting into the collectors field; interesting stuff though.