红
hóng · HSK 2
red
🧧 红 = 纟(silk) + 工(work); silk dyed red was a craftsman's prized work
The silk radical 纟marks fabric; 工 (work) hints at the sound 'gōng' → 'hóng'. Red-dyed silk was festive and prestigious, so 红 extends from the color to meanings like famous, popular, or in vogue.
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.