i-adjective
red; crimson; scarlet; vermilion
General color term for red. Kanji variants 紅い (crimson/deep red) and 朱い (vermilion) are used for specific shades, especially in literary or traditional contexts.
彼女は赤いドレスを着ていた。
She was wearing a red dress.
In autumn, the crimson leaves are beautiful.
i-adjective
Colloquial, often derogatory term for a communist or leftist. Capitalized 'Red' reflects the political label.
彼は赤い思想の持ち主だと言われている。
He is said to hold Red (communist) ideas.