Yep! Just like the title suggests, I would like to see an option to have a different-colored background. Maybe we could have them in red, blue, green, yellow, black, white, or silver.
By the way, we already have purple, so there's no need for me to suggest it, JS.
Perhaps you could also have different Pokeballs as well depending on the color. (Red - Regular Pokeball or Cherish Ball, Blue - Great Ball, Net Ball, or Dive Ball, Yellow - Ultra Ball, Green - Nest Ball, Yellow - Fast Ball, Quick Ball, or Park Ball, Black - Dusk Ball, Night Ball, or Luxury Ball, White - Premier Ball, Silver - Heavy Ball, etc)
So yeah! I would like to see this implemented if possible.
