I recently started using ChreeyTree on a new laptop running Windows 10 64 bit, whereas my old laptop had Windows 7 64 bit. I noticed all my text was in a non-monospaced font. When I highlightewd some text, and selected Formatting -> Toggle Monospace Property, things went back to Monospace (good), but now the text is all highlighted (bad).
I toggel the monospace property, and the highlighting goes away.
It appears to have nothing to do with Text color background.