noun, noun which may take the genitive case particle 'no'
rainbow-colored; iridescent
Describes something that has the colors of a rainbow, often used for visual descriptions.
Rainbow-colored soap bubbles floated in the sky.
彼女は虹色に光るドレスを着ていた。
She wore a dress that shone in rainbow colors.
Standard kanji spelling.
Kana spelling is common in children's materials and when the kanji is not needed.
Compound of 虹 (niji, 'rainbow') + 色 (iro, 'color').