Plants are "easy" planets. They absorb carbon dioxide, emitting oxygen, vivifying for the person, in the atmosphere. Living plants have green color, pleasant for an eye, which is a symbol of health and natural freshness.
Plants have green color thanks to the high content of a green pigment, chlorophyll. This adhesive is necessary for implementation of chemical process under the name photosynthesis thanks to which there is a processing of carbonic acid for receiving nutrients and release of oxygen in the atmosphere. Photosynthesis is carried out in so-called chlorolayers, green plastids which contain in cages of plants. These chlorolayers contain a chlorophyll and they are concentrated in stalks or fruits of a plant, however most of all in leaves. In succulent plants (cacti) all photosynthesis happens in a thick stalk. In order that in a plant the photosynthesis began, the chlorophyll absorbs light, solar or artificial. As soon as light gets on a plant, the pigment begins to work, but it absorbs not all light waves, and only those which have necessary length. To a certain length of a light wave there corresponds a certain color of a light range, from red to green. At the same time colors from red to blue-violet are most quicker absorbed, therefore, at the same time photosynthesis happens quicker. Green color of a range is not absorbed by a chlorophyll, and is reflected. As a human eye is capable to distinguish colors only by the light of, at a view of a plant he observes the operating photosynthesis process, and sees only reflected, green, color. After absorption of sunlight in a plant chemical reactions begin: water from a root system connects to carbon dioxide. Formation of nutrients (glucose) thanks to which there lives the plant and which bring benefit to the animals and people consuming them is result of such reactions. The plant contains also other pigments called to carotinoids. And, when the amount of light begins to fall (for example, in the fall), the chlorophyll in a plant collapses, carotinoids paint it in yellow or red colors. The plant switches over to a regime of economy: takes away all remained useful substances from leaves, and then dumps them.