Well, what do you mean by "green"? Do you mean "which reflects or emits light of these particular wavelengths", or do you mean something about human perception

Well, what do you mean by "green"? Do you mean "which reflects or emits light of these particular wavelengths", or do you mean something about human perception? Also, similar questions apply wrt "invisible". If "green" is based on human perception, why would not an entity which, when a person looks in their direction, does not really see them like any shape, but rather, perceives some greenness in that General direction? Why would this entity not be considered both green and invisible? Alternative, does "invisible" mean to the naked human eye? What if the entity is microscopic?