染まる
そまる · somaru · JLPT N1 · verb-godan
to be dyed
染 — water 氵 + nine 九 + wood 木
染 depicts the dyeing process: 氵 (water) for the dye liquid, 木 (wood) for plant-based dyestuffs, and 九 (nine) suggesting repeated dippings to deepen the color. Originally meaning 'to dye cloth,' it later extended to figurative senses like 'to be influenced' or 'to contract' (as in illness).