Hi Rob, welcome.
As Martin said the Hegner rollers are white. (Maybe white nylon ?)
My Hegner has had many years of heavy use (many hundred) blade changes in that time. I purchased the saw new and it came with a spare set of rollers, so was expecting these to be consumable parts, but I am still on the original set, which are showing little signs of wear.
I would get a replacement set from Hegner, its one of the few spares from Hegner, which are inexpensive.
Take care.
Chris R.