Question: Why the snow is white ?

Hi!
The colour of any object depends on what happens when light hits it (light can get reflected, absorbed, scattered or transmitted).
For example, one object that looks blue will reflect the green light to your eyes and absorb all the other colors.
In the case of snow, when the lights hits all the compacted crystals that compose it, none of the colours get absorbed more than the others but instead they all get reflected. So all the colours that compose light (the same ones you see in a rainbow) combined together make white and because they are reflected back, white is the colour we see.