Red or Green?

There are currently a set of temporary traffic lights on a major road junction in my home town of hull, due I think to the main traffic lights being upgraded. Because this is a major junction which already had white "Stop" line markings in theory no additional signage is needed, however the contractors have placed out the signs they always place at temporary roadworks, which are normally a legal requirement as there is no painted white stop line. Following so far?
You will no doubt be familiar with the signs, whcih read "STOP HERE WHEN RED LIGHT SHOWS."  All well and good, a clear and concise message we are all familiar with. However, on the other side of the road is a similar red sign with white lettering but bearing the message "WAIT HERE UNTIL GREEN LIGHT SHOWS" Essentially the same message, the result is the same you would think. But is it? The wording of the firts sign is the approved wording we all know and love (or hate in many cases) The wording of the second sign is however, probably the safer of the two. Imagine the situation whereby the red bulb in the traffic light system fails. Following the wording of the first sign there is now no red light showing, and the other lamps are also all off. The driver then takes it literally and drives on - no red light is showing. Now imagine the same scenario with second sign. No red light is showing, BUT no green light is showing either, and until it does, following the direction of the sign you cannot move off. Much safer surely? And if the green lamp bulb were to fail, it is still safer - you would eventually get frustrated as no green light is showing, but you could not pass into danger.
Whilst I doubt the legality of the wording of the second sign, and I have to admit in 26 years of driving I have never seen it before, you just cannot fault the logic.One of those occasions were somebody got it wrong to be so right.