Currently a small green label is associated with transmitted photos (red, if the transmission failed). But this label is not saved permanently.
It would be useful if, after successfully transmitting a photo, the color code is set automatically to a predefined one. This would allow to recognize ex-post which photos have been transmitted (to whom, depending on the chosen color code, e.g. red to client A, blue to client B). Currently I can do this manually, but it is tedious when implementing a workflow: edit photo 1 -> caption -> transmit -> edit photo 2 -> caption -> transmit.