N/A. Yellow ligt does not penetrate fog any better than any other color -- that's a common and pervasive misunderstanding. Hilldweller has already linked to the article I was going to point at.
Maybe "penetrate" is a confusing term.
I know from experience that a blue light for example is terrible for seeing in fog...and that yellow/amber light allows me to see more than I can with a blue light.
The eye sees the yellow better than it does the blue, less strain on the eye, etc.
Daniel Stern, etc, also mentions this IIRC.
In addition, the article cited in posts above is really more about falling snow than about fog.
Fog can be quite small particle-wise, with some studies indicating 40-50 nm range particles, ~ an order of magnitude smaller than even the yellow spectrum.
The cut-off for fog is 50 um, as larger than that is classified as mist instead.
Most fog particles are considered to be in the 0.2 - 50 um range.
0.2 um = 200 nm
200 nm is about half the wavelength of yellow light. This can induce scattering attributed to sub-wavelength effects.
As the fog particles are present in a range, some can induce scattering due to these effects, and some won't.
I'd assume that one fog system might be courser or finer than another...so that there is no one particle size distribution for all fogs. The nucleation sources, etc, will be different and the resultant fog particle sizes will reflect that.
Generally, nucleation mode particles are smaller, with aitken, accumulation and course modes being progressively larger...but course mode is still everything larger than 0.1 um.
So if nucleation mode is in the <0.02 um range, aitken in the 0.02 - 0.1 um range, and accumulation mode in the 0.1 - 1.0 um range...there are certainly periods of any given fog system that will be present in sub-wavelength ranges.
This means that a shorter wavelength light source will reduce the required particle size that can induce glare. This is analogous to IR systems being able to see through this sort of thing better, etc.
All that means is that some proportion of the fog present might be small enough to induce glare from scattering effects, and the actual amount of this effect can be expected to vary immensely depending upon the actual fog you are trying to see through.