瑕不掩瑜

xiábùyǎnyú
  1. lit. a blemish does not obscure jade's luster
  2. the pros outweigh the cons (idiom)

CEDICT

small defects cannot obscure the great virtues; the pros outweigh the cons

Wiktionary

瑕，玉的斑点。瑜，玉的光泽。瑕不掩瑜比喻事物虽有缺点，却无损其整体的完美。

重編國語辭典

事物的小缺点无损其整体的完美

維基詞典

Entry Composition

1 瑕 xiá
  1. blemish
  2. flaw in jade
2 不 bù
  1. no; not so
  2. (bound form) not; un-
3 掩 yǎn
  1. to cover up; to conceal
  2. to close (a door, book etc)
  3. (coll.) to get (one's fingers etc) caught when closing a door or lid
  4. (literary) to launch a surprise attack
4 瑜 yú
  1. excellence
  2. luster of gems