The color green is almost exclusively used in connection with plants in the Bible, and the meaning is closely connected to the meaning of plants as well. Plants, in general, represent facts, knowledge that we can gather from the world. Green plants are ones that are alive and growing. Since life represents love and goodness, it makes sense that green plants are facts that have the potential for good use. It also indicates that they are the kinds of things we learn through directly through our senses, since to identify green plants we need to actually see the greenness.

(References: Apocalypse Explained 507; Apocalypse Revealed 426; Arcana Coelestia 7691)

1529. It is very well known in heaven, but not so well known in the world of spirits, where so great a light comes from, namely from the Lord. And what is astonishing, the Lord appears to celestial angels in the third heaven as the Sun, but to spiritual angels as the Moon. There is no other source of light. But the intensity of the light angels experience depends on how celestial and spiritual they are, and the nature of the light depends on the nature of these qualities. Thus the Lord's celestial and spiritual itself shows itself before angels' external vision by means of the light.