(Probably stupid) clarification about supply paths

[Gresbeck]

When I see a region coloured in green in the supply map, can I assume the enemy cannot trace a supply path through that region, or is it possible that both factions can trace a supply path through the same region?

[Hobbes]

No. Both sides could have >= 25% control and be able to trace supply.
It just shows that you have a fair supply in the region.
Chris

[Pocus]

in ACW green means your supply can travel there, and as says Chris, both side can have enough control in a region for that. But slight note here: it does not means you have a fair supply level (this is the BOA filter which shows that!)