I can see wanting color coding.A number of years ago, I did a bunch of research and that pointed me towards the Scepter cans. The metal cans are more prone to developing rust which can cause leaks over time. There were some other considerations too, but I forget at the moment. Regardless, the Scepter cans are great and have a variety of accessories that will attach to make water filtering or whatever easier, but they also require a sort of large wrench to tighten and loosen fully (I'm sure you could get by without it, but it's an easier way to make sure). The biggest issue I had was that I wanted blue cans for water and red for gas. Most Scepter cans are tan and it was difficult to find the exact ones I wanted and I didn't want to paint them or rely on a label. Also, their red fuel cans were not US Govt safety approved (no pressure relief valve, like all newer approved cans have that tend to leak; which might be why the military has used them despite no "civilian" use approval) so I ended up having to order them from Canada. They are very thick and heavy duty. Haven't used them as much as I intended, but they've held up great for the past 7 or 8 years.
Good deal on the French surplus cans. Glad you found something that'll work.
Scepters are still pretty easy to ID even with the same color, even if the "fuel/water" stamp/mold/inlay is obscured by a carry strap (or whatever).
1 handle = water.
3 handles = fuel.
Plus all our surplus water scepters have the mini access cap inserted into the standard large cap.