The green ones are abugidas, which like Japanese Kana usually represent consonant-vowel pairs: https://en.wikipedia.org/wiki/Abugida https://en.wikipedia.org/wi

The green ones are abugidas, which like Japanese Kana usually represent consonant-vowel pairs: https://en.wikipedia.org/wiki/Abugida https://en.wikipedia.org/wiki/Abugida, instead of single sounds. Unlike in Japanese Kana, which originated from Chinese characters, in an abugida consonant symbols are modified by vowel diacritics.