When an icon has a red border, it means that it targets any player (you or an opponent).
A card that removes red-borded resources, may remove those resources from any one player (this effect may also be performed partly, or not at all).
A card effect that reduces production of a redbordered resource must be performed, so if your opponent doesn't have that production, then you must lower your own production or not play the card at all.
A card with a red-bordered tile icon targets any or all players' tiles.
A card with a red-bordered tag icon targets all cards with that icon, whether they belong to you or another player.