I joined just to share my view on this topic, so that should show you how much this option really is appreciated and used
I managed to switch to markdown because of joplin. It was the only app with markdown that works with linux and android at the time when I was looking for a new one (cca 2018/2019). Previously I've used evernote and google notes and whatnot for some personal stuff (and ended inventing my own marking system before I discovered markdown exist); cherrytree for lecture and tech notes (2013-2019); before that I think I've used notecase after txt files in folders ended being too cumbersome - when you want to search.
Now I use private github repo and .md files and edit them in atom for tech and lectures/meetup notes, so atom covers organisation, and I have benefit of versioning. Joplin I intensively use for more personal stuff, general todo lists and convenience of editing and viewing from the phone. And google docs for collaborating with my language teachers during online lessons.
I prefer markdown and only editor mode, mostly because I like to be able to edit when I notice something, without toggling the view and then scrolling to the point (in both setup, atom and joplin).
I like colors because I don't need to parse text in my head for meta meaning, I can skim through colors and locate fast what I want.
Yes, I have tendency for having very long notes, that's why I went with atom, in order not to hold everything in one db but still have it easily accessible. I had to split my first cherrytree into several db files (totaling 160 mb, but loaded with pics).
Joplin cannot work with several db files, right?
My note repo is around 9 mb and joplin db is 4 mb, both only plain text, so that'd be a few thousand pages if printed out
So, I'm definitely a heavy note-taking user.
I realized that I can tweak atom md colors several months ago, and yesterday thought about if something similar would be possible with joplin. Spend whole night tweaking and I'm very happy with the result.
Answers to why is CSS important feature for me, especially userchrome.css:
- took me just several hours to get great results
- there's no currently available theme that fits my needs
- they either have too little color, or colors they use are too intense, or they're light
- I had the same situation with atom themes available for download, so that means that what bunch of people like, I don't
- I've checked using default ones on both editors (I was at version 1.0.x until few hours ago and oh boy, was the upgrade awesome )
- if only option is to do custom theme, that would take me insanely longer
- and I suppose I should have to tweak (and understand) all components, and not that I could be able to change only 10-20 colors with the theme?
- unless you have in mind some plugin that would inject css into current theme (and with that solved the wish below)
- I don't have time nor desire to create my own themes and I really appreciate when small tweaks are available for apps I use
- to the point that I'd be ready to pay some (small) amount for (unlocking) such feature (ok, this isn't common reasoning I guess)
- no clue what plugins can do, I've just discovered them today, but when I looked at one, it also looked complicated like a theme compared to several lines of css
-  I'd very much like to see option for this css edit on android app as well, or ideally, importing this one, since I'm using it even more often than desktop one for editing
- it would be great if we could disable preview on android and have just markdown, plus awesome would be if cursor position could be remembered
- to the point that I'm willing to learn android to help with it, since I doubt I can figure out alone how it could be done, so I won't offer myself for that, unless it's really easy
Thanks for the great editor