Early morning runs in newfallen snow can be some of the most memorable. Hypothermia, frostbite and falls are some of the risks. It gets dark earlier these days, and a lurking attacker cannot be heard as well with headphones on. During the months with shorter days you need to rely on your auditory senses even more. Light colored material is visible even without a strong light source.
Reflective materials work only if there is a light source.
Blaze orange becomes poorly visible at night. However, during snowy days, dark or bright colors provide visible contrast and attract solar energy. Warm air will be trapped between the layers. Use clothing with vents and zippers to allow excess heat to escape as you become warm. It is better to feel a bit underdressed and chilly as you start out.