I would love to see Flying be added as a type. It’s been confined to colorless for awhile, and with the introduction of the Dragon type, Flying is now the only type that’s lumped in with colorless without any real purpose.
Give it a sky-blue coloring, a wing symbol, and call it good.
The types that have been introduced after dark and metal have been for pokemon usually defined as colourless so I believe that flying is the only other type we will possibly see other than a new one altogether, there needs to be some colourless pokemom though so what would we say qualifies as just colourless type? Would it just be used for alternate typing such as the new ho-oh set to be released with xy9.
As great as it would be for us collectors to have each type represented, I think the addition of a card color for each type would just make the game itself just too complicated. Too many specific mechanics for each type would be needed, and it might just make the game too intimidating for younger players.
The idea of a white ice type and light blue flying type gets my juices flowing though.