朱红
zhū hóng · HSK 7
vermilion
🟥 朱 (cinnabar red) + 红 (red) = vermilion, the bright red of old lacquer
朱 zhū is the red of cinnabar, the mineral once ground for pigment and ink; 红 hóng is the general word for red. Together they name vermilion, the warm orange-red seen on temple gates and traditional seals.
红 — silk radical 糹/纟 + work 工 (phonetic)
红 is a semantic-phonetic compound. The silk radical 糹 (simplified 纟) signals the meaning, since the character originally referred to a kind of pink or light-red dyed silk. The right side 工 supplies the sound. Over time the meaning broadened from the dye color to 'red' in general.