Several parts combine into one character.

Compound ideograph with a striking origin: 人 (person) above 卩 (a kneeling person, or stylized human face). The encoded meaning: "the look on a person's face — their complexion / countenance". Anger, joy, fear, embarrassment all show in skin color, so 色 originally meant "facial expression / complexion". From there it generalized to "color" in the abstract — every hue is, in a sense, a face that the world wears. Identical across 繁體 / 新字体 / 简体.

The etymology survives in modern usage: 顔色 (yánsè / kao-iro / 안색) carries the dual meaning "color" + "complexion / mood". When a Mandarin speaker asks 你脸色不好 (nǐ liǎnsè bù hǎo) — "your face-color is not good" — they mean "you don't look well", not "your skin is the wrong color".

Mandarin: sè, falling 4th tone. 颜色 (yánsè, color), 彩色 (cǎisè, multicolor), 特色 (tèsè, special features / distinguishing characteristics — used constantly in branding and reviews), 红色 (hóngsè, red color), 黑色 (hēisè, black). Note: in Mandarin "色" alone can also have a sexual / erotic connotation in certain contexts (色情 sèqíng = pornography), so the standalone character carries some ambiguity. Compounds like 颜色, 彩色 are safer.

Japanese: TWO on-readings split by tradition. ショク (shoku) is dominant — 原色 (genshoku, primary color), 景色 (keshiki, scenery — irregular hybrid reading: kei + shiki), 染色 (senshoku, dyeing). シキ (shiki) appears in 色彩 (shikisai, hues / coloring), 色気 (irokke or shikike, sensuality / charm). Kun-reading いろ (iro) is the everyday word — 色 (iro, color), 赤色 (akairo, red), 色々 (iroiro, various — repeated marker). The doubled 色々 is one of the most useful Japanese words: "various / many kinds of".

Memory aid: a face above a kneeling figure — what colors a person's face becomes the word for color itself.