The informations that come from our eyes are normally elaborated by the brain. For instance, when we look at some snow during a sundown we think that it is white. But is it really? Think carefully, the answer is no. The snow takes the color of the sundown, so it is red, yellow or even blu!

In this picture the white balance is completely missing, so everything has taken the color of the light at that moment. This tutorial will show you how to correct those colors.

Select the Eyedropper tool () and make sure to select in the status bar "5 by 5 Average".

In this way the Eyedropper will analyse the image in blocks of 5 pixels for a more accurate result.

Add a new adjustment layer by clicking on and selecting Color Balance.
You should try to get rid of the blu color, in my case I concentrated on the midtones:

and I almost did not touch the shadows and highlights.

Create a new layer selecting "Levels".
Normally every color channel should be corrected cutting out the noise, but in this case it is useless so we are going to concentrate just on the RGB channel. Click on this tool and choose a part in the image that should contain a middle (50%) gray. If the result is not satisfactory you can always try another time with another area.

You will see a drastic change in the colors:

Create a third layer selecting "Hue/Saturation".
Select the Blues in the box at the top and click on the snow where it is still blu, and then reduce the saturation untill the snow lose this blu shape:

Select the eraser tool and erase the Saturation layer on the sky as it has loose some blu:

Equilibrate the light of the image with Shadow/Highlight:

And it's finished: