Is there a reason why...
LEDs in smart lamp heads cannot have a bank of narrow wavelength emitters mimicking the old sodium lamps?
Interestingly one published survey where old sodium lights were replaced with new, 6000°K, LED lights gave the following result:
40% reported that the new lights were better, 44% reported that the new lights were neither better nor worse, and 16% reported that the new lights were worse.
Our local council cited the report in defence of spending £m with one of the councillor's cousin's company, stating that more than twice as many people found LED lighting to be an improvement than those who had a problem with it, and therefore majority rule, it was a good investment even without considering the long length of time the electricity savings would take to repay the outlay.
A neighbouring council cited exactly the same report when asked why they hadn't take the initiative that our council had, claiming that the majority of people found LED lights made no difference to them, and that therefore they couldn't justify the capital expense required currently for the energy saving offered which was cost neutral at around the 20 year mark, but that they would reconsider if costs fell or if other factors arose which required wide scale lighting renewal outside of the normal cycle.
Another neighbouring council, again in response to a question about not taking the initiative to update lighting, used the same report to say that 60% of people found that LED lights made either no difference or were worse than the existing lighting, and therefore it would never be an initiative they would take unless forced by legislation, as well as the council being suspicious over the actual savings estimated.
TL;DR version, opinion is divided on the matter.