2 suggestions

[wya123]

One, could they install a warning when you deplete a resource, similar to when you exceed capacity?

Two, and off topic a little, but since they are doing such a great job updating classic strategy, could they maybe buy the rights to Imperialism? I can't get it to run on Vista anymore and I miss it too!

[Ijuin]

I have never seen a resource deplete in this version of Colonization, though I know that in the original you could deplete Ore and Silver resources by mining them for long enough.

[samsmithnz]

I think he means when your factorys run out of raw goods (e.g. your rum factory produces 12 rum, but only 6 sugar are produced in the city)

[Ijuin]

Oh I see. Something like "New Amsterdam is set to produce Cloth, but there is no Cotton available".

[wya123]

Yes, that and when your carpenter has become superfluous due to a lack of wood, etc.

[johnmcd]

That would be a good improvement.

Another suggestion:
- have a map option to block the north and south passages with ice, ie, if you want boats on the Pacific you have to build them there, make the wild west properly isolated.