Sorry guess i shoulda added what they are best for: these are mainly for Medium bright to bright days. I wouldn't suggest using these for foggy days. If you are looking for foggy i would suggest HI persimmon, Pink iridium, maybe HI yellow (not sure that would be so hot, but better than fire i would say). But the fire brings out every bit of shadow in the snow. Like you will be able to see every piece of crud snow that isn't flat it kinda brightens it up with a blue hue and increases contrast from my experiences. If anyone would like to add or correct what i have to say feel free, but it's just what I thought when I looked through my friends wisdoms with a fire lens. I mean they look cool, but they perform sooooo well. Sorry I didn't even think to add what they did. Hope this is a decent explanation for you.