Yes, color does affect plant growth. Colors
are simply different wavelengths of light that are
reflected by objects back. For example, plants
look green because they have a lot of chloroplast
in them, which absorbs all visible wavelengths of
light except green, so leaves look green to
Different colors are associated with
encouraging different parts of plants to grow.
Blue light will allow the plant to grow leaves and
other vegetation and red light with blue allows
the plant to grow flowers. The plant does not
absorb the green light so does not use it to grow.