Generally a "throw" light will work better for you. It doesn't have to be a super narrow angle neecssarily, the key is that there be as
little spill as possible -- this is the main theory behind vehicle fog lights, they are positioned low to the ground -- so that the backscattered light won't dazzle the driver, and they direct the light low to the ground. They are not "pinpoint" lights, either.
The biggest reasons why incans are generally better suited is because of the way their filament emits in all directions, as opposed to into a ~150 degree forward angle, nearly all the light is capture as part of the beam, with relatively little spill. LED lights are the opposite, most actually transmit more light as spill than as part of the main beam. In a foggy situation, this creates two main problems:
1) the target isn't receiving very much light as a smaller fraction of the total lumens are captured in the beam
2) the greater percentage of the spill gets back-scattered by the fog, obscuring the target
Now, LED lights that use TIR optics I find work fine, this is because they have almost no spill. The wavelength/ color temp is not nearly as significant as beam profile for fog.
and lower frequency gets reflected less and won't blind you as much.
Sorry to nitpick on the physics here, but there are a few things I'd like to clarify:
I believe you mean lower wavelength (eg "bluer" light), instead of frequency. Either way, in the case of rayleigh scattering, or scattering off the air molecules themelves, blue is scattered more -- that is why the sky is blue. However, that effect only applies when the particles doing the scattering are smaller than the wavelength of light.
Water droplets in fog, which are much larger than the wavelength of light, reflect all colors indiscriminately.
However, for practical purposes, very cool white LEDs are still typically worse in fog for the following reason:
1) our eyes are more sensitive to shorter wavelength light in the dark, so the dazzling effect is worse
2) most objects in nature, such as trees, dirt etc. absorb blue. ie, if you were to use a monochromatic blue light, it would be useless as just about anything you try to look at will only reflect very little of that light, but the fog would reflect just as much of it as with any other color.