THIS circuit will be reliable because any collector to base leakage current in one transistor will tend to turn off the other one. IT is a simpler version of the output circuit in a lot of power amplifier designs. It would also work to put a single LED current limiting resistor in series with the collector of the NPN transistor.Since it's a quick edit - here's the circuit I've built and worked.
View attachment 197866
And here's the LED's in the edited version:
View attachment 197867
When signal is High, the upper transistor conducts, bypassing the green LED and the red LED is lit.
When signal is Low, the lower transistor conducts, bypassing the red LED and the green LED is lit.
With that - I'm done.