When I was using Sublime Text, I found Monokai as a great visual appearance, but when I started typing markdown files I noted that it missed highlighting some pieces. Then I found Monokai Extended and it solved my problems.
When I moved to Atom, I found Monokai and so I was at home .
But then Atom published One Dark, I gave it a try and really liked. And for some cases I prefer it over Monokai.
I understand that Syntax Themes tends to be made for / tested in, specific languages/grammars, so I was thinking that if instead of defining a Syntax Theme for your entire Atom installation, you could choose a different one for each language/grammar. Like you choose Preferred Line Length / Soft Wrap, etc, today.
What do you think?