At the SKA route, in at least one case the signal aspect in the HUD is shown as green, instead of yellow. I have seen this issue before in TSW2020 for RSN. I never reported this, but I think this is a general bug for more German routes.
To my understanding the signal configuration can´t be shown correctly in the hud. The top main signal shows green = pass and yellow = reduce speed to 40 km/h till next signal (unless it says something else on top of the signal). The bottom pre signal shows double green = expect green and max allowed speed at next main signal. So it´s neither only green or yellow. I might be wrong though.
The green and yellow means proceed, but @ 40km/h. That's why you get the green aspect on the HUD. The use of the HUD makes the sim a bit arcade-ish and that's the reason I turn them off
I know how German signalling works, but usually slow down is represented by yellow. Into my opinion green means, continue with he allowed track speed.