while the GFMD CSS theme capitalizes the words the way they are in the source Solarized Dark CSS Theme Capitalizes Every Word Regardless Of The Way The Source Is.
That’s intended by the author of the style. You can change it yourself if you don’t like it. (But I would suggest you modify your own copy, like “Solarize Dark customized”.)
while the GFMD CSS theme capitalizes the words the way they are in the source Solarized Dark CSS Theme Capitalizes Every Word Regardless Of The Way The Source Is.