Change footnote background color?

I thought at one point (this past summer) my footnotes where a different color, not the current grey. I’m not sure if this was a function of a previous version or a setting I changed (that maye have been defaulted since then). I can’t seem to find a references setting to change the footnote background. Is it possible? If so, how? Also, would this affect the oh-so-cool “Ghost Notes Mode”?

To my knowledge, that has never been possible. You can change the text and border colour for annotations by placing the cursor in the annotation and invoking the colour palette (Cmd-Shift-C), but footnotes have always been grey.