Without light there is no colour. It is not that that we just don't see colour; there isn't any. This is because the colour we see is a reflection of a portion of the light spectrum. Green grass reflects the green portion of the spectrum while absorbing the rest of the colours.
This doesn't mean however, that when there is light there are a lot of colours, as seen here in these winter shots. They are not black and white with tones, but full colour. The low, early morning light with two primary tonal values, light and dark, help create the monochrome effect.
f/4 1/4sec 45mm
f/4.5 1/2sec 70mm
f/8 1/2sec 28mm