bleed someone white, to

bleed someone white

Extort money, take someone's last penny. For example, That contractor would have bled the department white, but fortunately he was apprehended in time . Presumably this term alludes to losing so much blood that one turns pale (and perhaps also to the idea that money is the life blood of commerce). [First half of 1900s]
See also: bleed, someone, white
The American Heritage® Dictionary of Idioms by Christine Ammer.

bleed someone white

and bleed someone dry
tv. to take all of someone’s money; to extort money from someone. (see also bleed.) The creeps tried to bleed me white. These taxes are going to bleed me dry!
See also: bleed, someone, white
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions

bleed someone white, to

To extort money, to take someone’s last penny. The term dates from the seventeenth century. One writer claims it was coined by gamblers; once a victim had been made to pay through the nose (lost all one’s blood through one’s nose), one was bled white. More likely the saying relates to the fact that money was considered the lifeblood of trade and commerce.
See also: bleed, someone
The Dictionary of Clichés by Christine Ammer
See also:
  • bleed (someone) white
  • bleed someone white
  • bleed white
  • cover
  • grab (someone or something) by the throat
  • grab someone by the throat
  • grab someone/something by the throat
  • get someone's dander up, to
  • help (someone) along
  • help along