The design is obviously based on WW2 era US Army HBT duck hunter camouflage (British-made example can be seen here) and Olive Drab M1942 HBT utility jackets, which the Netherlands would have received as aid during WW2 and the Dutch Indonesian War/Indonesian National Revolution immediately after (1945 – 1950). This camouflage pattern went into limited service in 1951, a year after that war ended so it was probably not used in Indonesia (source: https://www.camopedia.org/index.php?title=Netherlands). Unlike the American version, this uniform is not designed to be reversible.
The uniform was tested by the Korps Commandotroepen (KCT; Special Forces Commandos), though it was not issued to other units since its colors were impractical for the Dutch countryside. There were also concerns that the camouflage was too similar to what the Waffen SS used during wartime occupation (source: https://strikehold.net/2021/02/23/new-camouflage-uniforms-for-the-dutch-armed-forces-the-backstory/).
Gas flap is removeable and buttons in.
Behind collar, for hood?
The sleeves on this particular jacket have been shortened and hemmed.