Shopify Developer needed for custom work

Details information for what is needed: sample here : [login to view URL] On the link you can see one main picture and the sub pictures below what i am looking for is to only display the sub pictures of the black and not all pics so when gold is selected it will only display the main gold and the sub pics of the gold item In this example i have created 4 variants each have its own SKU but i see in the product detail page it shows the pics of all no matter which is selected which doesn't make sense to me. Shopify support told me that this can be fixed by a developer who can modify the Themes / html files