Custom shape auto font color

[voltavidTony]

Hello, I'm making a custom shape, and I want the text labels to use the "auto" color, like for instance in the "Dual In-Line IC" shape, where the text is white in dark mode and black in light mode. I've tried <fontcolor color="auto" />, <fontcolor color="default" />, <fontcolor color="strokeColor" />, but those values don't seem to do anything. How can I insert text into a custom shape that responds to the color theme of the application?