As these two DO lenses are very different from all the ones we've seen before, especially in terms of price, I think we'll see DO in a lot of upcoming Canon Tele lenses.
If that is the case, rebranding a large chunk of the highest end lines from the iconic red to this (in my opinion extremely ugly) green does not make sense.
In any case, these newer lenses are have nothing but the focal length in common with previous DO teles. Slapping something in them that links them to other market segments does not make sense. We don't have separate colors for IS, USM/STM or BR elements, why do we need one for DO?
I give you my permission to get some coloured (your choice) tape and apply it to the end of the lens barrell.
Problem solved.
Personally, I prefer my long lenses to look anonymous.
Canon was way to successful in marketing the red ring L glass that the green ring immediate makes me think it is inferior and the mark I 400 DO and other early DO lenses didn't do it any favours. Going forward I am fully expecting all the fast super-tele lenses to be DO lenses and red ring L lenses.