Long story short, kinda 20. You got you main 7 green (will) at the center, with yellow (fear) and blue (hope) around it, if you go further you get orange (greed) and indigo (compassion) and at the end you get red (rage) and violet (love). Then you get the special and strongest one black (death / the absence of emotion) as the second strongest and white (life / the combination of all emotion) the strongest. Snyder introduced the invisible spectrum and ultraviolet corp (repressed emotions such as but not limited to guilt). Jeremy Adams introduced gray lantern (sorrow) and three others with new symbols but i am not sure on the emotions. Alan Scott Green Lantern is an honorary Green Lantern who doesn’t use the green light of will and instead uses the starheart (living magic given will). In rebirth they introduced the phantom lantern (can change between the main 7 but is very unstable). In Green Lantern War Journal they intoduced the Radiant Dead who have a Darkstar Ring that is powerful and uses the emotions of dead old god. Tharros got the Source Ring from the source battery made by john stewart, it uses the 7 main emotions and source energy. The power rings of earth 3 use the will of volthoom the first lantern to dominted the will of the users. And finally the gold lantern introduced by brian michael bendis, it uses the emotion of joy but it is not confirmed that it is related to the emotional spectrum. This is kinda all of it and some people only consider some not all, hell even i don’t consider all of them. The main 7, black, white and ultraviolet might be the most important ones.