Green is a primary color that sits between yellow and blue on the color wheel. Opposite colors are also known as complementary colors, and they are the colors that appear on the opposite side of the color wheel. In the case of green, the opposite or complementary color is magenta.

Magenta is a vivid shade of pink that sits between blue and red on the color wheel. It is a unique color that has no corresponding wavelength in the visible spectrum. Magenta is created by mixing red and blue light in equal parts, which is why it is sometimes called the “non-spectral color.”
There are several ways to understand why magenta is the opposite of green. One way is to look at how our eyes perceive color. Our eyes contain three types of color receptors, which are sensitive to red, green, and blue light. When these receptors are stimulated in different combinations, we perceive different colors.
When we look at a green object, the green receptors in our eyes are most strongly stimulated, and the red and blue receptors are less active. The brain interprets this pattern of stimulation as the color green. On the other hand, when we look at a magenta object, the red and blue receptors are both strongly stimulated, and the green receptors are less active. This pattern of stimulation creates the perception of magenta.
Another way to understand the relationship between green and magenta is to look at their color properties. Green is a cool color that is associated with nature, growth, and harmony. It has a calming effect on the mind and is often used in design to create a sense of balance and tranquility.
Magenta, on the other hand, is a warm color that is associated with passion, energy, and excitement. It is a bold and vibrant color that commands attention and can be used to create a sense of drama and intensity.
When used together, green and magenta create a striking contrast that can be visually appealing. This is why they are often used in design, art, and photography to create bold and eye-catching compositions.
For example, a photograph of a green tree against a magenta sunset sky can create a powerful and memorable image. Similarly, a design that combines green and magenta elements can create a dynamic and visually interesting layout.
In conclusion, the opposite or complementary color of green is magenta. This relationship is based on the way our eyes perceive color and the color properties of green and magenta. Understanding the relationship between complementary colors can be useful in design, art, and photography, as it can help create visually striking compositions.