Just to round off the thread - I ordered it from Paddock Perfection who were very helpful and only too happy to swap the green tape for white.
It arrived on Saturday and I set it up this afternoon.
I've set it up initially to try and keep the pigs away from the henhouse, which they keep moving around, as a single-strand roughly 18" above the ground and connected it to a 44Ah 12V car battery and solar panel to trickle-charge it.
First reactions from the piggies was a very loud and unimpressed squeal, followed by a leap and a gallop round the paddock. So, that works
![Smiley :)](https://www.accidentalsmallholder.net/forum/Smileys/default/smiley.gif)
Hamish did initially go the wrong way, into the henhouse area but soon found his way back out again (with another squeal) so I might try lowering the tape a few inches, but I'm sure they'll soon learn to keep their distance from it.