and my response from Subway ....
Dear Ms Sparklechick (name changed for privacy reasons)
Thank you for your enquiry regarding beetroot in the Subway sandwiches. At present we do not have beetroot as our formulas come from the US.
We do trial some items from time to time. Maybe we may trial beetroot some time soon.
Thanks for your email. We value our customer's feedback.
Kind Regards
Donna Cargill
Operations Manager
Subway Developments