We really like white horse tape for the electric, the pigs see this clearly, and you can also quickly see if the pig has rooted earth over it.
Pigs are intelligent, and quickly learn that it's the white stuff they avoid, whereas straight wire is more difficult for the pigs to see and differentiate from non-electric wire. Once they have learnt the sows don't go near it, much of ours in the sow units is off for most of the year !