Its a really fickle thing but...
When I refer to Gary/Blue as Green and people always try to correct me and say "its not green its blue." NO! His original name was Green dangit. He was only called blue because we only got blue from Japan. And people tell me i'm wrong for thinking that way. I called Red Red, "Gary" Green, and the female protagonist blue [and sometimes leaf]. Its also kinda annoying when people say blue because I don't know what blue their referring to. Gahh I just wish Green has a consistent name like Reds D;
I kinda just wish everyone would call him green, including gamefreak. Cause red and green are complimentary colors =w=; and I like the name better.
My generation was so screwed up lol!
I just go by the English names listed in the main series games, and since I regard the games as the highest form of canon (as they were the first Pokemon canon), I go with "Blue." I refer to the female protagonist of Kanto, who never really comes up in conversation all that often in my experience, as "Leaf."