It's not a color like in a webpage. It's a measure of how many x-rays were received by the scanner, and presumably the background and the object both look the same.

Making the person stand sideways would sort of work, but it wouldn't be hard to shift the flaps of an open jacket while turning.

> have the background colour of the display changed

Have you thought this one through?

Don't be ridiculous.

Billion is the new million.