I am looking for a circuit to use a dual color LED as an idiot light next to a guage in my car. And I would like the led to flip between the two colors when triggered. I'm planning on a grounding trigger. When car is running , the voltage will be approximately 13.8v to 14.3v and the voltage to the LED's needs to be 1.5 of course , so voltage drop can be included in the circuit if that's easier . Other wise i have used a 470Ω resistor for the voltage difference . I think a flip of about once a second would be about right , but a way to change the flip/flop rate would be fantastic ,maybe a resistance variable to fine tune it .
My background is in automotive stereo installation and old school auto repair , so i have some knowledge of electronics . Basically i can follow a circuit diagram but not up to designing one .
Please feel free to ask any questions .
Thank you for any help with this project , I appreciate it .

 

Hi, maybe these threads can give u some ideas:
http://forum.allaboutcircuits.com/showthread.php?t=14706
http://forum.allaboutcircuits.com/showthread.php?t=5956

Additionally, I'v seen somewhere a type of bi color LED that blinks with the color changing with no any additional circuit. only need battery, it blinks.

 

Maybe you can try this circuit

 

LEDs, 555s, Flashers, and Light Chasers

This article has several examples of what you want to do.