The project I am working on requires a color indicator which shows the current state (either red, green, or yellow).
Ideally the indicator would have a large surface area so you can quickly glance at the device and determine the state. 2" x 2" would be nice.
The device is battery powered and would ideally be able to operate for months at a time without recharging.
What would be the best solution to use for this kind of application?