The Thinkspace platform supports the ability for vendors and retailers to upload multiple images and associate them with specific metal types. That way if a customer clicks "White Gold" on their dropdown, it will show the white gold product image.
This tutorial specifically addresses how to use that feature as a retailer working in their admin.
To start, log in to the admin of your website (yoururl.com/admin).
Next, click on Catalog and find the item you wish to edit.
When you find that item, click "edit variants" as seen below:
Add in all of the metal types (and prices) you want on the next screen, and click the image button on the far right by each one to select the corresponding image(s) that you want to use for that metal type.
Drag and drop 1 or multiple images for the metal type selected
Close and save. Now that product should change picture when the customer selects different metals