Adding to this: Wagtail rubber is brick red as it comes from the factory. It darkens over time with exposure to UV so you have a rough idea how beat it’s getting from the sun.
I buy Ettore rubber by the gross, cheapest and we use one a month too.
I’ve Left my wagtail in the bed of my pickup over an afternoon in summer here and it was black when I found it the next morning. Useless. I leave it in a covered bucket wet or in the cab now.