Change iphone xs color

You could sell it and take the proceeds you get plus the difference and buy a new one.

You can go to an Apple Store and talk to the manager and see if there is anything they can do for you. How far past 14 days is it? And when did you receive it?

There is no white, there is a silver. If the iPhone was purchased within the past 14 days it can be returned for a refund and then buy a new one in the color of your choice.

And when did you receive it?

If you have a store near you go to it, tell them you need to speak to the retail manager on duty and pitch your story.