[BC] Need for traffic signal-style timing light

[James Potter]

Folks:
I want to make/buy a Green-to-amber-to-red traffic signal-style light set run by a timer to signal remaining duration of live TV segments. It should be settable for max overall duration, with the amber light goes on at a preset minute or percent interval, and the red light at the end of the duration.  Anything like that around COTS? (Cowboy:  Commercial Off The Shelf). Or existing home-brew?  Where is Popular Electronics Magazine when you need it? (RIP Pop 'tronics).

Thanks/Regards/J