In some fanfictions, Prof Oak is bashed for being too traditional. He might be stuck in old ways of training and evaluating Pokemon and trainers. So a fanfiction could explore how his old - fashioned methods are holding back the development of new training techniques and the growth of trainers in the Pokemon world.
Another reason could be character development for other characters. By bashing Prof Oak, it allows other characters, like young trainers, to shine. If Prof Oak is shown as wrong or unfair, it gives the trainers a chance to rise above his unjust actions and prove themselves, which makes for an interesting story arc.
In a Prof Oak fanfic, the mention of blue or green Spearow could be really interesting. Maybe the color difference represents some special abilities or origins. For example, a blue Spearow might be a rare mutant form with enhanced flying speed compared to the regular ones. And a green Spearow could potentially have a closer connection to nature, like being better at finding hidden berries in the forest. However, without reading the specific fanfic, it's hard to say for sure what the significance of these colored Spearow is.
One possible plot could be about an adventure where Prof Oak discovers something rare that is blue in color, numbered 39 perhaps. It could be a new Pokemon with unique abilities that Prof Oak then studies. Maybe it has a connection to some ancient legend that he is trying to uncover.
Obviously, Prof Oak would be one of the main characters. And perhaps a young trainer who is helping Prof Oak in his research related to the blue 39 thing. It could be a trainer who has a special bond with a certain type of Pokemon that is somehow related to the mystery.
Often, in these scenarios, Ash might face challenges that test his determination and the support from Prof. Oak and his mom plays a crucial role in his development. There could also be unexpected friendships or rivals that come into the picture.
Since I haven't read the fanfic, I can only guess. Obviously, Professor Oak would be one of the main characters as the title implies. There might be a young trainer who has a connection to either blue or green Pokémon (maybe they specialize in water or grass types) and is the one who has to decide whether to forgive Prof Oak.
In a Prof Oak fanfic, a blue or green Spearow could be a symbol of change. The normal Spearow is brownish - red. So the different colors could mean that something in the Pokémon world of the fanfic is changing. It could be an environmental change, like a new type of energy source in the area that is affecting the Spearow's appearance. It could also be a sign of a new era in the Pokémon training world where different - colored Pokémon are starting to emerge with new abilities.
The 'Blue or Green Forgive Prof Oak' fanfic could have a really interesting plot. Blue and green could stand for different Pokémon teams or regions. Prof Oak might have had some sort of betrayal or error that affected these regions or teams. The act of forgiveness could be a long and drawn - out process. The fanfic could explore the emotional journey of the characters involved, how they come to terms with what Prof Oak did, and how the blue or green aspects play into the overall theme of forgiveness, like perhaps certain Pokémon from those color - related aspects help in the process of forgiveness.