Seems odd to 'reply' to my own post, but I picked up a book on Sunday which covers the area. It is Commandant Emile Lavisse [trans Capt Edward P Lawton, US Army], Field Equipment of the European Foot Soldier 1900-1914, Nashville; Battery Press, u/d reprint of 1902 original. In the Russian section it gives "B. A waist belt of dark leather, with a plate. C. Two cartridge boxes of yellow [sic] leather, each of which holds 30 cartridges." Seems odd [to me anyway] that it doesn't give an actual colour for the waist belt, just 'dark', so it still doesn't provide the full answer!