It’s positive and metered logic. For metered logic a green IO is an IO with voltage present (with a meter). Positive logic is for “active low” inputs. When it’s set to positive logic, green means the input is active whether it’s an “active low” or “active high” input. Unfortunately, the way it’s implemented isn’t that black and white. It only changes the way some of the inputs are displayed and it works differently for different controllers. The best example is a TAC20. They have both active high and active low inputs so you’d think you want to use positive logic but green is shown as the active state on metered logic, then reverses some of the active low inputs when you put it on positive logic. So for it to make sense it’s best to just remember that TAC20 and older like TAC50-03, TAC50, & TIV should be on metered logic and anything newer than that like TAC50-04, TAC32, etc. should be on positive logic.
And for IO injection, red turns the IO on or active and blue turns it off or inactive.
And while we’re at it, everything should be on 8 bit ports except controllers with PMI cards like TAC50, TIV, TIII.