Sometimes the light bounces around inside the ice crystals before being scattered making the snow seem to sparkle.
White light source spectrum.
Almost all of the light is reflected or scattered by the air and water molecules so the snow appears to be the color of sunlight white.
By scanning changing the measurement beam path length relative to the reference beam a correlogram is generated at each pixel.
When white sunlight enters snow very little of the spectrum is absorbed.
Some full spectrum light sources are also marketed as emitting ultraviolet uv radiation as well as visible light.
The frequency of light that we see as red is being reflected and we see that shirt as red.
Black and white are a bit different from other colors.
The sun is the most obvious.
Blue light emitted from such leds can be used to stimulate a wider spectrum of emission from a phosphor layer around the led casing or can be directly combined with red and green leds to create white light.
White is a combination of all colors so when we see white the object is reflecting all the colors of light the same.
White light can be generated by a variety of sources both in space and by artificial sources on earth.
The width of the resulting correlogram is the coherence length which depends strongly on the spectral width of the light source.
For example the sun and other stars are sources of white light.
However it was the invention of the blue led that led to the creation of new efficient white light sources.