The colours of these insulators make me think that they were dyed. The red insulator is marked by Whitall Tatum. The yellowish insulator and the purple insulator are marked by Hemingray. Lastly, the other insulator is marked by Armstrong. Note: the yellowish insulator has more orange then it appears in the photo, and the purple insulator has more purple than it appears. Any help would be appreciated, thank you. :)