This is a TEST product to show you how it will look like if you use Custom Field: Generic Child Variant. In this DEMO, Diesel Sweater is parent product and all others are child products. Black, Grey and Mahogany colors have stock, and Navy/Blue is Out of Stock.
The parent product is set "not orderable", so "Choose a product variant first" text shows off instead of "add to cart" button. 

Color options and stock info

Mahogany = In Stock

Navy/Blue = Out of Stock

Heather/Grey = In Stock

This Custom Field option is good if you want to show different product pictures for different attributes. To get the same thing in your website; make sure that;

• "Parent Orderable" is UNCHECKED
• "Display parent as option" is CHECKED