For what its worth, I've had selective yellow headlights since february of last year, and I dont see myself going back. I live and work in southwestern PA, and my daily 45 minute commute winds me through washington county. I see fog nearly every day on my drive in to work. I also see the benefits (literally) of them in other conditions, such as driven rain, and snowy conditions.
I find that for most nighttime driving, I cant really tell the difference in color perception when there arent other cars around, other than greatly reduced glare from roadsigns (of which there are significantly more than necessary, let me tell you, and each spaced and aimed *just so* to minimize your ability to spot critters emerging from the woodline).
I actually find driving other vehicles, especially vehicles with higher cct lighting (a friends 2014 corolla with the led lowbeam) or even normal halogen lighting, to be uncomfortable now. Significantly more glare and reduced ability to see through evening/morning fog. The only advantage is in heavily urbanized areas, where you do encounter more blue colored objects/vehicles.
Im pretty sure Im going to stick with selective yellow for a good long while. I dig it. I drive a ton at night. I have a company truck (2017 f250 with the quad headights) that i will probably add selective yellow auxiliary low/highbeams to (stock headlamps are terrible for drivong on lease roads and winding around west virginia. There doesnt seem to be much of an intensity difference between the center portion of the beam, and the taper to the edge of the beam. There is also a very noticeable cutoff effect, even when the highbeams are off, which makes even low-speed driving (typically 15mph on lease roads) uncomfortable to navigate the winding/twisting roadways, and the lack of any center "punch" to the beam means that all of the excessive (imo) foreground light dramatically drowns out the beams reach.
To bring the conversation back to the point at hand, I have a set of LED Cibie super Oscars (the 14watt draw 75k candela versions). I love them. Theyre fantastic, especially considering the extremely low power draw. The biggest issue is the literal glaring one: they are 6000k led's. Super blue. The beam pattern is fantastic, the reach and spread are simply amazing, but even the slightest hint of haze/fog/moisture in the air renders them practically unusable. I am tempted to tint the lenses with paint, but I know Ill pay a big hit in output. I tinted the lens of ancheap light bar I had laying sround to selective yello. It was effective, but cut the output dramatically due to how cold blue-white the led's were. LED lighting is probably the way to go, but unless we see mass adoption of much lower cct led's in the auxiliary lighting world (looking at you, Cibie, JW Speaker and Grote), auxiliary lights that are useful putside of perfect conditions will continue to be far and few between.