New attribute in attribute sets for old products

[eonegin]

When I add new attribute to attibute set (like 'second color') I see it when i add new product with that set of attributes, but in old products I don't see it in "Associated Products" -> "Quick simple product creation".

How I can solve that problem?

We use Magento 1.9.3.

[Benabee · Accepted solution]

"Quick simple product creation" displays the super attributes used when you created the configurable product. You can't change the super attributes once the configurable product is created.

A customer requested me the same feature. He wants to add a configurable attribute to an existing configurable product. If you're interested, I can add the feature in my software