The Amish believe in living “plain,” and that means no “fancy” bright colored accoutrements such as luminous reflectors, clothes, curtains etc.
Of course there is nothing about reflectors in the Bible, but there is plenty about living humble and piously.
I wouldn’t argue with them about their interpretation of the Holy Scriptures, or their customs.
Romans 12:18 (KJV) If it be possible, as much as lieth in you, live peaceably with all men.
These are the same people that build an out building for their phone service. If it isn’t in the house, it is ok. There are Amish that hide television sets in their walls. I guess they think they are hiding from God AND the government. They already don’t pay taxes... Religious exemption.
If they use our roads, let them pay.