let's see the color of your money

let's see the color of your money

cliché Show me proof that you have the ability to pay (for something). Sure, I can do that for you—but let's see the color of your money first.
See also: color, money, of, see
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

color of your money, let's see the

Back up your claim with hard evidence. A twentieth-century Americanism, according to Eric Partridge, it originated in gambling or betting, as a challenge or to make sure that the bettor actually had enough cash to cover a bet. One writer holds that it was already common in eighteenth-century England, but his citation is not verifiable. In any event, it is unlikely that the actual hue of the money was in doubt, unless the questioner felt it might be counterfeit. More likely “color” was used figuratively for something readily identifiable.
See also: color, of, see
The Dictionary of Clichés by Christine Ammer Copyright © 2013 by Christine Ammer