RTNI also remember the device I saw it on back then in the Westerwald region: It was a smart white SABA, I'd guess it was the T 6716 color telecomputer, if my memory serves me correctly. My parents had a certain eye for good design.
Information about the device can be found here: https://ia903406.us.archive.org/30/items/saba-programm-1974/Saba%20programm%201974.pdf