Will photography change the background color?

This has nothing to do with the exposure mode, but a white balance problem.

It is estimated that you use automatic white balance, and the color of clothes accounts for most of the picture. The machine will basically determine the white balance by the color of the clothes, so the background will be slightly biased.

Manual white balance can be used.

In fact, it is also possible to set it to automatic. After all, you mainly restore the color of clothes, and the background is secondary. You can cut the picture, it's just trouble.