How to swap one single LED for two color one that will change color depending on state
A simple circuit like this should work:



simulate this circuit &ndash; Schematic created using CircuitLab
Use the LED current to activate a transistor base (Q2). when it's on, D1 will sink the current and Q1 can't be activated.
When Q2 is off, your constant current source activates Q1 base and D2 will light up.
The circuit toggles between D1 and D2 based on Q2 status.