Erich and Wojtek are both right. If the leather trousers/jacket were not used, there was also a 'suit', to the same pattern, made from heavy-duty cloth material, I think artificial fibres, such as Rayon, although also in cotton canvas originally. This was a dark blue-grey, more like RAF blue than the Luftwaffe uniform colour, and the collar was a very dark grey, almost black looking, astrakhan-type 'fur'. The zip liniers on this latter kit were more prominent, being of a slightly lighter material, more so after wshing etc, and show in B&W photographs as a lighter grey line.
In addition, many pilots wore a black, or dark brown, leather 'bomber jacket', over their uniform jacket or Fliegerbluse if the latter was worn, with either the leather or cloth trousers already described. As many of these were obtained from 'private' sources, there doesn't appear to be a definite pattern to the design, although many resembled the American A1 jacket, but with leather cuffs and waist band, instead of knitted wool.