I'm working with this drawing to indicate the switch on a distribution panel on my boat. Green/OFF & Red/ON. 12vdc One trouble is that the total ma is quite high when you add up 8 switches. http://www.instructables.com/id/The-RedGreen-LED-Guide/step2/null/ I'm thinking it would be more efficient using transistor gates as in this 2nd drawing down on this page, but that's a single led and I want to use green/red bipolar for switch OFF/ON. Understanding Transistors Thanks for all your help.
The trouble with using power (lamp or LED), well, no matter how you do it, it's still power.
Green LED is ON for when switch is OFF. Red LED is ON for when switch is ON.
No matter how you switch the LED's (switch or transistors), those darn LED's still consume the same amount of power.
Using transistors to switch the LED's on and off actually consumes a tiny bit more power.
If you want to use a "bipolar LED" (I'd call them anti-parallel) like that, then you need to pick a resister that works for the voltage you have with both LEDs. Then you need an H-Bridge. Schematic example below: