A simple circuit to toggle between LEDs based upon input voltage
Here is an arrangement that was on all my industrial power supply modules, and boat switchboards, that let you know if you have No-power, blown-fuse or OK, with a single led.







simulate this circuit &ndash; Schematic created using CircuitLab

Over the years I have made quite a few arrangements with bi-colour that transition from green through orange to red giving you an excellent view of what is happening in a single led.