ContentControl Placeholder Background color

Hi everyone,

I need your help to figure out how to get the index of a content control placeholder background color. As you can see in the attached file I was able to successfully apply a colorful background to the placeholder with ..Range.Shading.BackgroundPatternColor. Now I need to do the opposite thing but regardless of the color I applied the index returned is always the same negative number that corresponds to the "default color" which is wrong.

Can someone help me get the color index?

Thank you in advance.

Massimo