Official colors

[Robert Vermaat]

OH,  The end of the fourth, the beginning of the 5th century, AD.

Sorry but I have never heard of such colour distinctions apart from the purple of course.
White was worn at very official occasions (including the military).
Red seems to have been the dominant colour for undecorated tunics worn under armour, but others occur as well (such as blue for naval troops), including different colours for decorated tunics.
Never have I heard of civil servants wearing blue only? 
Same for maroon, or 'black and white checkered capes'.