1. Click "Go To"

2. Click "Variants"

3. Click on the variant to add the SKU

4. Select the option

5. Add the value and derivate value

6. Click "Save Changes"

7. Click "Add Existing Item"

8. Select the item to add

9. Associate the option with the new SKU (in this case, the color)

10. Click "Add Item to SKU"

11. Click "Save Changes"

12. Click "×"