Emissive is an adjective that means having the power to radiate light.
The Latin prefix E-M-I-S-S refers to something that is ‘emitted’ or ‘sent out.’ Emissive may be used in a scientific context to refer to radiating light, or more informally it may simply refer to something like colors being emitted. For example: The cinematography of that film is stunning. I like the emissive qualities of that scene where the red lights shine through the dark sky.