着色
ちゃくしょく · chakushoku · JLPT N1 · noun
coloring
🎨 着 = put on, attach + 色 = color: coloring is attaching color to a surface
着 (chaku) means to put on or attach, and 色 (shoku) means color, so 着色 is applying color onto something. The same 着 appears in 着る, to put on clothes.
着 — sheep 羊 (top) + eye 目 (bottom)
着 originated as a variant of 著, which depicted plants emerging visibly above ground (grass radical 艹 over 者). Over time 着 split off to carry meanings like 'attach,' 'wear,' or a verb suffix marking ongoing action (zhe), while 著 kept senses like 'manifest' or 'author.'
色 — person 人 (top) + kneeling figure 卩 (bottom)
Originally a pictograph showing one person above another, traditionally interpreted as depicting facial expressions or intimate posture between two people. The earliest meaning was 'facial expression' or 'countenance,' which extended to 'appearance' and eventually 'color' (the look of things). The 'shǎi' reading is a colloquial variant used for everyday color words.