Don`t go past that way too often, but that open sodium lantern looks awfully familiar. I have spotted that one up there a couple of times going past on the motorway and always wanted an excuse to go and have a closer look, at least Google have been to visit now. Saw it lit too one morning, I think that was when it first caught my eye. Could it be a Phosco P112
? Looks similar. There are one or two other vintage lanterns around there too by the look of it, but no other open ones I can find. Like the proverbial rocking horse poo, those things are.
As for slightly pinkish lamps, I find sometimes ceramic metal-halide/Cosmopolis can look a bit pink, depends on what it is compared to. Normally it has a somewhat "incandescent" warm-white tint to it. SON is blatantly orange by day or next to anything anyone would call "white light", but some of them can look pink when side by side with a SOX lamp. White SON is largely out of use these days as far as I know, and didn`t really make it outdoors (was more common for retail lighting) so would be surprised if it were one of those.
Don`t know if it`s my eyes playing up these days, but comparing mercury to quartz metal-halide, sometimes there is a dim violet glow around mercury-fluorescent lamps, which halide doesn`t seem to have. This is especially noticeable when they are off in the distance a bit. It could be caused by the greater content of UV light produced by mercury lights, where the shorter wavelength of the deep violet/UV is more difficult to focus compared to the rest of the visible spectrum, causing it to blur.
Other ways to tell them apart include the lamp shape and finish - generally mercury lamps are elliptical with a white coating, while halide lamps take on a clear tubular shape. There are elliptical halide lamps produced too, but they don`t seem as common these days. To confuse things, there are also clear tubular mercury lamps, but those are particularly rare, and emit a ghostly cold white colour of light.