Don't be too hasty. Take a very close look at the photos posted by Werger above. Do you notice the little "tic" marks running down the middle of the shoulder harness (draped outside the cockpit) and the parachute harness strap (to the left of the photo, inside the cockpit)? That's because the shoulder harnesses were made from the same cotton webbing as the parachute harnesses. The material from the factory, is white and the "tic" marks are black. Once in a cockpit and seeing use, they quickly became dirty, so rarely appear a bright white in vintage photos, but they started life a bright white. As for the lap belt, which is a wider and different material, it was usually khaki or a light shade of green. The darker green shade belts are typically found post-WW2. There is also a rectangular pad of thick brown leather that is found underneath the lap belt buckles.