浅(qiǎn) - shallow; light (colour) in Mandarin

浅 (qiǎn) covers two ideas English keeps apart: physical shallowness, as in 水很浅 (shuǐ hěn qiǎn), "the water is shallow", and pale colour, as in 浅蓝色 (qiǎn lánsè), "light blue" or "pale blue". Once you notice the pattern, colour terms across Mandarin use 浅 (qiǎn) and its opposite 深 (shēn) the way English uses "light" and "dark".

浅 (qiǎn) also extends figuratively to mean "shallow" in the sense of simple or lacking depth - 这个道理很浅 (zhège dàolǐ hěn qiǎn), "this point is simple/obvious" - though that use is milder than the English insult "shallow person", which Mandarin expresses differently.

The colour sense trips up English speakers who default to 浅色 for "light" and forget it needs the noun 色 (sè), "colour", attached when talking about shades generally rather than one specific colour: 浅色衣服 (qiǎnsè yīfu), "light-coloured clothes".