Mark Lauckner made this set of commemoratives for us, and explained why one of them came out in a great "multi-tone" red as you can see above.

The "multit-ones" are not because the glass is of different colors, but it has to do with the rate of cooling. The screwtop cools the fastest, and is more on the yellowish side. The bottom of the skirt cools moderately fast, and that ends up more of an orange. The "core" of the insulator, where the glass is solid, from the lower wire ridge up to near the top of the hex head, is the brighter red.

Use "view original" to see lots of detail!