So let's say I have a configurable product having an option of colour with 2 values: Black, White.

I want to make the thumbnail images of the parent product stay, even when I select any colour.

Here is my parent product:
[![enter image description here][1]][1]


And this is my child product:

[![enter image description here][2]][2]


  [1]: https://i.sstatic.net/NxTA5.png
  [2]: https://i.sstatic.net/Lx9p1.png


So can you guide me how to do that?
Without re-adding images. 
I'm using Magento 2.2.1