Green is symbolic of all things natural or biological, and carries an overall positive vibe to the viewer. Strongly linked to environmental concerns, it is also a color that expresses regeneracy, and therefore concurring concepts such as hope, life, growth…
Being the most organic color, green is often considered relaxing and reassuring to the human eye. But green also has other, more or less positive connotations in traditional culture; it can be associated with sickness, luck (or lack thereof , and thus the concepts of chance and fate) and monster-like creatures, such as dragons, reptiles, etc.
A few facts
Green is a secondary color, meaning that it is traditionally obtained by mixing the pigments of two primary colors: blue (or cyan) and yellow. It is however one of the three components of the RGB (Red, Green, Blue) system, which is based instead on the addition of light.
Its temperature is cold. The more blue you add, the cooler it gets. Inversely, the more yellow you add, the more it will convey energy and warmth.
Being a mix of yellow and blue pigments, the complementary color for green is the third primary color: red (or magenta). This means that red will be the color that has the highest contrast with green. If you mix green and red pigments, you’ll get a brown hue. On the other hand, the mix of green and red lights will produce yellow.
How you may use green
Obviously, green is the safe, traditional color for all your environment and nature-related communications. It is particularly true if you use it in combination with brown, which symbolizes the earth, trees, plants… If you mix brown with green, you’ll get an olive tone which will appear very earthly and reassuring, but may also come across as conservative, old-fashioned and lacking dynamism.
As stated before, the closer it gets to yellow, the more it will convey a feeling of warm energy. But be careful about juxtaposing green and yellow; both colors can be associated with sickness, so be sure to use bright, vivid tones in order to produce that feeling of energy. You may also want to avoid applying green or yellow-tinted filters on an image featuring people for that same reason. Alternatively, if you really wish to combine green with a warm color, then orange may be a safer option.
If you want a cooler feel, then you may use blue-green tints, or a juxtaposition of green and blue. Keep in mind though that a cool effect is precisely what you will get. The same is true if you combine green with grey. Those associations work best in technical and scientific fields, where you want to emphasize reason over emotion.
You’ll obtain the boldest contrast by associating green with red. The mix is catchy to the eye and if it is too intense for you, you may play with tints to create a less dramatic balance.
However, keep in mind that because red is the advancing color and green the receding one, it is red that will stand out over green.
Green may not be the color that is most frequently used in painting, except in landscape painting, where the depiction of natural elements is so crucial. Claude Monet’s Poppies is a famous example of the use of complementary colors, a field of experiment for Impressionist painters. In this case, Monet plays with red and green.
Also, because red is the warmest color of the combination, by contrast green will appear even cooler to the viewer.
Finally, you may add white to create a light, soft tint of green that will increase its soothing power, somewhat reminiscent of water. Be sure however to combine your pastel green with a bolder tint or color, in order to avoid appearing dull and transparent.