COLOURED SURFACES.
The wavelengths reflected by a surface determine
the colours that humans perceive.
For example, a green plant only reflects the
green wavelengths and absorbs all the others.
Thus, the plant appears green.
When coloured light falls on a white surface,
it completely reflects the incident light and takes
on the colour of the light. That is why a white
wall appears reddish when illuminated red.
Illuminating a coloured surface with coloured
light creates mixed colours.
When furniture fronts or a wooden floor are
illuminated, they reflect shades of brown that
bathe all neutral surfaces, such as a white
ceiling or wall, in a warm tone.