Any customer can have a car painted any colour that he wants so long as it is black.

People can have the Model T in any color - so long as it's black

I will build a car for the great multitude. It will be large enough for the family, but small enough for the individual to run and care for. It will be constructed of the best materials, by the best men to be hired, after the simplest designs that modern engineering can devise. But it will be so low in price that no man making a good salary will be unable to own one...

You can have any color you want, as long as it's black.

An American can have a Ford in any color so long as its black.

Any colour - so long as it's black.