So speed knobs are the work of the devil along with amber tophats, lol.
I actually have some spare black pick up rings and a poker chip, might give it a go. Although the black knobs I have are speed (devil) knobs.
In real life the dark flames have a lot more contrast against the red. The photos have not shown it at its best.
black pup rings
black toggle switch and poker chip
Bring the darkness!