I need high contrast theme

I just downloaded Joplin-2.14.20.AppImage on Mint 21.3 xFce, and I found I cannot use it. I need black background and white text. From the themes preinstalled there is not high contrast theme. This is configured on my system already, I have black background and white text everywhere, but Joplin doesn't use this system settings. And the themes are gray, not really black and white. There is gray text on gray background so it is really hard to read to me and I just cannot use it. And if there is some configuration like any css files somewhere inside Joplin-2.14.20.AppImage I cannot set it when it is not installed, but just binary.

Will you add high contrast themes? This is really tiring.

There is nothing built in, however you could try set the theme to "Dark" and then add these your custom CSS, both for rendered Markdown and Joplin itself (see Options → General → Appearance → Show Advanced Settings).

:root {
	--joplin-background-color: black !important;
	--joplin-color: white !important;

Restart the application to see the effect. Of course, more tweaking will be necessary to make everything use higher contrast, but it's at least something.

Thank you. After the change it seems better. But the text in the content of article: "# Welcome to Joplin!

Joplin is a free, open source note taking and to-do application, which helps you " it is still gray color (the text color). I used Aritim Dark them, and then I have added the styles.

I have changed the view now and IDK how to get it back, but I mean the view in the right area. It is the bad color, the gray-blue shade.

Yeah, you would need to inspect the specific theme and then override its styles with custom CSS. It's a job that requires quite a bit of time and testing to make everything look right. I personally also like higher contrast, but for me it's the other way around, meaning black fonts on white background, hence my own modifications concentrate on making fonts black instead of grey, etc., so they won't be very helpful for you here.

No problem with that, but are the css files - themes installed after the first run of the app? I think I did it wrong I should better use the wget command

wget -O - https://raw.githubusercontent.com/laurent22/joplin/dev/Joplin_install_and_update.sh | bash

But now the app image is on my ssd.
so the themes were installed onto disk to have +w permission.

Probably there ain't tool to inspect the styles like in FF/chrome development tools.

There are no custom CSS files created by default, but you either create them by hand in your Joplin profile folder or simply use the GUI to do it (as described above in https://discourse.joplinapp.org/t/i-need-high-contrast-theme/37033/2).

Please check Help → Toggle development tools. You probably only need to change the colours defined in :root to affect the whole UI and notes.