Yes, first run.
Looking at my Yunsil set now, in what I consider normal light, the fabric hits the absolute dead center between gray and brown. I couldn't tell you what one color it actually is.
I think it's only because the movies were set in warm climates, that the pants looked brown, because the colors were warmed up. But if there was ever a scene with Indiana Jones in a snowy mountain, you'd say his pants were gray.
All in all though, the 'new' fabric swatch that Yunsil provided will be good. You can see that it's a very close match to the original, just a shade or two darker. Everyone should be satisfied with that color.