I dunno, really! I think it might be the green? xD But really, it was because I was with two other friends years ago when Black and White came out, one chose Tepig, the other chose Oshawott and I decided to complete the circle with Snivy, and it's stuck with me since. :)
How're you doing with Pokémon GO? Have you managed to run across any more Team Instinct players? :o