Cortana text is too dark, how can I lighten it?

[jimpict]

Cortana text is too dark

The text Cortana displays at the top of her window on Windows 10 is really dark. I can't seem to figure out how to lighten. I keep playing with the theme, but this doesn't change. Everything else is fine. All the other text is white on this dark theme. The only thing wrong is this text at the top.