It's more complicated than that. Filters work well light sources that produce a full, continuous, and even spectrum but less predictably on sources with uneven or discontinuous spectra. (Which only stands to reason.) Folks have attempted to measure this in a number of ways; most famously with a scale called the "color rendering index." This worked pretty well until LEDs, but the measurement was approximate (since it uses a relatively small finite number of samples) and LEDs found the holes. There's some pretty good discussion of the limitations and criticisms in the
Wikipedia article on the subject. Huge piles of paper have been spent on trying to compensate for the disadvantages. And different people will doubtless perceive them differently, as our color vision isn't uniform. (They might, for instance, be less troubling to someone with red green color blindness, as they are particularly poor at rendering reds.) Note that there is a difference between the perceived color of a reflected light, which might be a very narrow spectrum, and it's ability to accurately illuminate pigments in related spectra, as pigmented objects typically reflect a broad spectrum of colors, albeit unevenly. (A blue car still reflects enough red that it can look red under red light. And the car can look quite different under a blue light than a white light, since the blue light is generally not a full spectrum.)
The basic problem with LEDs is several fold: they do not produce an even, full spectrum. (The better ones come quite a lot closer. But they are also much more expensive.) They tend to produce a lot more blue light than traditional incandescent lights of the same color temperature. Take a picture of a room lit with two different strings of Christmas lights; one LEDs and the other traditional incandescent lights. You will find that even if you perceive the lights to be similar one picture will look rather yellow and the other quite blue. This isn't an illusion. Our brain to some extent adjusts for the color of the light . . . but not the color of the photograph. As a matter of fact, many cameras will automatically adjust their white balance, which would tend to mitigate this effect, but I find that they don't do so terribly well with LEDs. (To truly see the effect you should set the white balance to manual and don't change it between pictures, but the effect should be visible even if you don't.)
For reasons I'm not able to expand on it seems that blue light causes considerably more eyestrain than longer wavelengths. This means that LED streetlights cause comparably more eyestrain on a lumen for lumen basis, thus to see the same benefit you would need to make them much brighter. This too has a cost, as it means the difference between the well lit and shadowed areas will be greater, which also causes eyestrain. (And makes it more difficult to perceive things in the dark . . . like a deer jumping out of a ditch.)
Next up, blue light interferes more with sleep patterns, as our bodies perceive blue light to be morning light. You want bright "daylight" lightbulbs in the morning and "soft" or better yet "warm" lights in the evening.
Another problem is the field. LEDs don't really produce a spherical field, which means they often don't work well with light fixtures designed for a spherical light source . . . like pretty much every light fixture you've ever seen. The reflectors and lenses simply don't work properly with LEDs. You can compensate for that with different kinds of fixtures . . . but that's another expense. (In fact, it's typically the primary barrier to getting theatres to use LEDs. They can't just pop an LED into their existing light fixture. It requires a completely new fixture, which is often hundreds or even thousands of dollars to an example and tens or hundreds of thousands for a completely new inventory.) So theatres will often add a few specialized wash luminaires, but they're often still reluctant to use them more broadly. And all those fixtures on the ends of all those poles have reflectors and lenses designed for High Pressure Sodium lights that do indeed emit a more or less spherical field. So short of changing the fixtures, you get a much less even light field.
The takeaway is that I, for one, find it physically unpleasant to drive through Midtown now. It hurts my eyes and I cannot see as well there. The eye strain problem is something that becomes more pronounced as you grow older. And . . . I'm slowly but surely getting a little bit older.
So don't get me wrong. I've sold LED fixtures. Phillips/Strand makes a line of fixtures using a light engine called the Selecon. It's great. LEDs surely have their place. I don't think street lights are one of them . . . yet. Something better than horror show around SLU might be possible, but it would be more expensive.
