The traditional form 紅 is a phono-semantic character. 糸 on the left means silk and points toward the original colour of dyed cloth; 工 on the right mainly supplied the ancient sound. The old dictionary Shuowen described 紅 as a pale red colour of silk, while its meaning later broadened to the everyday “red”. Simplified 红 keeps the same two-part structure in a lighter form. This seal-form-inspired sketch shows knotted silk beside 工.
A piece of culture
A colour for celebration Red is prominent at Lunar New Year and many weddings, where it can express celebration, happiness and good wishes; details vary by family and region. A familiar example is 红包 / 紅包, a red envelope containing money, given on occasions such as New Year or a wedding. The colour carries the message, while 包 — a character you already know — means the envelope or packet.