Kontrol S4 MFPro - How do I know which track I am controlling?

I am wondering because, when i was using the X1 the A and B would change yellow, depending upon which track i was using. (If I remember correctly, its been a while)

Now that i am using it with the S4 both the A and B stay blue when i switch focus, i am not sure which track i am going to beatmash until i actually press the button. There has to be a way to tell... I hope. Anyone have any clue on this? Any help would be much appreciated.