>>57911413This plus even in Japanese they've used either load words from English or the English word (spelled out phonetically in Katakana, as is typical for foreign words) for the versions since Crystal. So looking for native Japanese words that are opposites/pairs and start with K and N is barking up the wrong tree in the first place.
It's ポケットモンスター クリスタル (Poketto Monsutaa Kurisutaru)
not 結晶(Kessou) even though they use the kanji for gold 金(Kin) and silver 銀(Gin)
It's ファイアレッド (Faia Reddo) and リーフグリーン(Riifu Guriin)
not 火赤 (Hi Aka) and 葉緑 (Ha Midori) even though the original red and green were ポケットモンスター赤 and ポケットモンスター緑
The English loan words for Ruby, Sapphire, Emerald, Diamond, and Pearl are all the most common way to refer to those gems, but they could have used 白金(Shirogane) for Platinum instead of プラチナ (Purachina)
Gen 5 uses ブラック (Burakku) and ホワイト(Howaito) Not 黒(Kuro) and 白(Shiro)
If they were concerned about very young players not knowing the kanji yet they could have used kana to spell it out, either switching to hiragana to indicate it's a native word they probably know or sticking to katakana to match the rest of the title because it's cool.
