The purpose of the Late Roman Draco standard.

[Robert Vermaat]

Would you then argue that the vexillum was "the physical representation of the emperor", as well?

Yes, that is a vexing question, because this would also be the first time a vexilla standard is mentioned as being purple in colour. My only thought on this is that the Draco windsock was purple, and that is borne out by the other descriptions posted, and the material was ripped from those standards, along with the purple adornment on the vexilla standards, which everyone assumes is normally red in colour (which I agree with having a number of colour photographs of vexilla standards depicted from murals and wall paintings, all of which show them in the typical red colour).

Well, there we have it - as the word for purple (purpure) can be interpreted as red as well, and vexilla have been known to be of a red colour, how purple was this 'purpure' in the case of Silvanus? Andeed of the other dracones? Bright purple or perhaps more red than we have assumed here so far?

The Fectio draco always has had a bright purple tail: