靛蓝色

• 艹(grass; plant)RADICAL
• 监(supervise; monitor (for sound))PHONETIC

Plants and grass are carefully monitored to extract the precious blue-green color.

• ⺈(knife; variant form)ASSOCIATIVE
• 巴(long for; cling to; stick tight)PHONO-SEMANTIC

Beauty as sharp as a keen blade makes people stick fast and unable to look away.