There were no markers on the pylons or wires as far as I know. There certainly weren't when I was there.
The authorities were once asked if they would put orange markers on the earth wire that spans from pylon tip to pylon tip but there answer was that as no one had hit the wire, there wasn't a need.
Before the runway was realigned, one pylon was pretty much in line with the runway centre line.
As I said before, the pylons were not much of a problem in reality - just don't drag it in on a low final approach.
15/33 is 551m IIRC with clear approaches/climb outs so no problem at all. 07 (06) was good fun with the trees on the appoach but again they were more pyscological than a real problem.
Sibbo has always been quite a busy place, movement-wise and this sad occurrence is, as I said, the first of its sort which proves it isn't a dangerous or difficult place to operate from. We operated Cessnas and a Seneca there and the parachute centre has had some relatively big stuff based there including the Skyvan and Let 410.