I don't think there is any doubt about what the color is (or, given color-blind drivers, which light is on); the only issue a law-abiding driver is supposed to

I don't think there is any doubt about what the color is (or, given color-blind drivers, which light is on); the only issue a law-abiding driver is supposed to consider, on seeing the yellow light come on, is whether one can stop within the remaining distance. Of course, in practice, it's more complicated... The practice of putting cameras on lights and then reducing the duration of the yellow light is not only an abuse of power but also dangerous.