Notes on future Pokémon pairs after Sun and Moon

While it is likely that the next pair will have an unrelated title duo to previous stuff but assuming we don't:




Color related:

1. Crimson and Indigo: The Japanese names for Red Orb and Blue Orb, these two can be another hot and cold duo of games.
2. Orange and Violet: Colors of Sun and Moon, both of these are primary colors that are described in the Pokédex, but appear in Minior's cores.

Materials:

1. Plus/Minus: Despite the earlier rumor, this actually makes a good idea.

Metals:

1. Bronze/Copper: Two of the trainer classes your PC can obtain in Gens III to V, these are also used for a Relic item, the Relic Copper, which is actually called Ancient Bronze Coin in Japan.

Already used concepts:

1. Light/Dark: BW already covered this, but we can travel back to it.
2. Dawn/Dusk: Same as above, though Japanese for Dawn Stone is Awakening Stone, while Dusk stone is Dark Stone.
3. Male/Female: Again, done in the last three generations, but more apparent version of this can be done.

 Others:

1. Brown, Pink, Purple: Other dex colors without games assigned to them, these can get something interesting in the future. 
2. Directions: So far, only Suicune has anything to with the directions, that being the North. Outside of it, East and West Gastrodon exist.
3. Seasons: Major mechanic in BW and its sequel, seasons are covered by the Winged Mirages