I'm working on a switching circuit for a guitar amplifier that uses one DPDT relay which is powered by 12V DC supply. A SPST switch (panel mount or footswitch) will power the relay and switch to a second amplifier channel.
Is it possible to wire a common-cathode RGB LED to glow one color (red) when relay is off and other color (blue) when relay is on?
The closest circuit I could find is this Alternating between two LEDS using BJTs but it has common anodes.
Is it possible to rework the circuit to use common cathodes?
If that's possible, I could bring a positive voltage to R4 when I turn the relay on.