Wile I'm at it, I'll post some of the Dutch uniforms of 1914-1918, and you'll notice there wasn't much difference.
You'll find out that pictures containing our soldiers wearing helmets are very rare, since we technically we not at war.
Also, a minor notice, the only dutch soldiers that wore helmets were the assault infantry, known in our native language as "Stormtroepen".
Here you see Dutch infantry with uniforms, but without equipment.
I'm not sure the guys with the shako's (the larger hats) as actual officers, weather they are conscripts or regular infantry.
Here we have a painting of Dutch soldiers, and their officer behind them, this picture also contains Queen Wilhelmina, who inspected our soldiers very often, wich was a kind of morale boost for us.
Notice that these men do not wear helmets as I stated earlier, also, this picture gives a more clear view about how the soldiers of 1914 looked like, as their uniform colours are clearly seen, I also assume they are equiped with Mannlicher K95 rifles, according to the looks of their bayonets, since the Beaumont rifle uses a musket-bayonet.
Originally, the uniforms of the Dutch "Landweer" as it was called were blue coloured, this because we were neutral trough entire WWI, we would only use the green/gray uniform if we would fight.