Nokon cables aren’t made specifically for wet and muddy conditions. But, provided you take care with fitting, this is probably the best cable system for mountain bike shifting efficiency, especially if you have a bike that demands tight bends along its cable runs.
The main advantage of the Nokon approach is that none of its parts can compress, but most riders buy it because it looks great and is lighter than standard cable outers. The individual anodised aluminium segments come in a range of colours. Downsides? They creak occasionally and aren’t the best solution if you slime-surf all year round.