Green
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.
(Reference: Apocalypse Explained 507; Apocalypse Revealed 426; Arcana Coelestia 7691)
John 14:16-18
16
I will pray to the Father, and he will give you another Counselor, that he may be with you forever,--
17
the Spirit of truth, whom the world can't receive; for it doesn't see him, neither knows him. You know him, for he lives with you, and will be in you.