The government must be seen to be whiter than white.

政府须让人觉得是清正廉洁的。

《牛津词典》

Behind him, there was a large choir dressed in whiter than white raiment.

他的后面，有一支庞大的穿著异常洁白服装的歌唱队。

youdao

Take care not to overdo it, unless you are working on a ‘whiter than white toothpaste ad’.

小心，别做得太过了，除非你是在做“比白色更白的牙膏广告”。

youdao

The Institute of Directors is among those bluntly saying it's shocked, and that government procurement has to be whiter than white or else companies won't bid.

BBC: First Class Fiasco