Dark surfaces radiate the minimum amount of heat, though. A perfectly black body will absorb all incoming radiation and re-emit it back by a Boltzmann distribution (according to its temperature). Less than perfect surfaces would reflect some the incident light/heat; if they reflect at the same constant or regular angle, we recognize it as 'shiny', while if it's a random angle, our eyes recognize it as matte/solid white.

Except it won't absorb anything if the snow reflects all of the light.

It makes sense to absorb heat when there is little or no snow, but it doesn't at all when snow covers all of the surface.

When there is snow and ice on the road the surface will is light colored (white or grey).