I see my theme in that list, but when I try to enable, I don’t see any changes. With the code snippet from my last message, I was expecting the number tag style items to be replaced with blue, strike-through text, but I am still seeing the same style as without my custom theme.
Just like that, it sounds like a bug. Or maybe your style is not overwriting the default one. Could you try dropping syntaxHighlighting(defaultHighlightStyle), in your theme?
I tried commenting out that line and I also tried swapping the order in the theme list and neither worked.