No, it is not because the aliens that are planning to take over our planet will be jamming up the systems so there's no way we can call for help when they arrive during the solar eclipse. (Well, at least we've not officially heard that being confirmed. Yes, I'm kidding for Pete's sake.)
Besides, if aliens were going to be invading our entire planet, who on earth would we call for help anyway?
Traffic signals have been around for more than a hundred years and have pretty much always used the same colors. Texas may be soon freshen up its color game.