[GreenKeys] Two color ribbon?

[Jim Haynes]

On Fri, 24 Jun 2011, Rokumon Cat wrote:
>  
> Did the model 28 have a mode that would alow the sending and reception of messages using a two color ribbon? On the 28 ASR listed on e-bay, they show it with a red and black ribbon. I thought maybe it might have been used in a Naval situation where there were classified and non-classified coms.
>  
Two-color ribbon was an option on the Model 28 printer.  So far as I know
it was under control of some received character, so the incoming material
could choose whether to print in red or black.

Now some of the European Telex machines, like Siemens, had two-color
ribbon that was arranged so that incoming traffic printed in one color
and outgoing in the other color.  I guess the could be helpful in a
Telex conversation where you want to show clearly which party was talking.
I don't know if Teletype equipment could be made to operate this way.
And certainly not the Model 32 for Telex.