Hey Slick, the 4 1/2 inch part of the the plate is parallel with the wheel.
The tire is black, the frame is silver metal.
Yes, they can be mounted vertically. However, they may or may not work depending on your application (how you'll actually use them) due to the load you need and your expectations for them.
They have a ~5/8" ID (bore) while using a 5/8" shoulder bolt.