Many of us like to get out and photograph fresh fallen snow. In one of my previous posts I went over how to keep snow looking white instead of grey. Click on the link for some Winter Photography tips. Another problem is when we head out and come back with a card full of blue snow images? What causes this? How can we fix it? The cause is how the snow reflects light. In bright daylight it's not a big issue but when you are in the shade the snow has this blue cast. If the scene is not being lit directly by the sun then its being lit by reflective light. So in essence the snow is being lit by the blue sky. This is why in shady scenes the snow looks blue.
It's not difficult to fix, in camera turn your white balance to shade setting. This is often symbolized by a little house with ray thingies coming off to one side, symbolizing shade. This will help with the blue cast, but your best bet is to shoot in raw and use a white balance correction in your photo editing software. The shade setting on your camera will get you close but it may not always be as accurate as you would like. Look at the before and after images below.
This image was shot without color correction.
This is with color correction added in post processing.
As you can see there is a bit of a difference in the images and the white balance. You will also notice the sky is much more blue in the original image. I used Lightroom's eye dropper white balance tool to select a snowy area that was lit by direct sunlight. This gives me white snow, and shady snow that doesn't look blue.
Now that you know how to fix the "problem" is it worth it? Sometimes I will keep the blue cast as it makes the image look and feel colder. This is another reason I shoot in raw. I can change my mind. Like most things in photography there is no right or wrong answer, it's what you prefer.