@narcell your question prompted me to do some work on it and I managed to put together a theme-picker plugin.
edit: now on github https://github.com/sebshader/color-themes-plugin
(after unzipping place the folder in your pd path, and make sure there are no other color -plugin.tcl files in the pd path)

It lives in the preferences menu
you can save the current (applied) theme to be used the next time pd starts by hitting "save", and if you select a theme from the list and click "Save as Dark Theme" then that theme will open instead if you're in dark mode when you open pd.

In order to stop using a specific theme for dark mode you can click "Delete Dark Theme"

I couldn't figure out a good way to include the text window and help browser colors, so those have to be re-mapped for the changes to be seen. I also had some trouble with the text highlight background color

In order to include more themes, put them in the "themes" folder inside. But only include setting colors in the files or else other things can get messed up when the list gets drawn.
@60hz I included your theme as well as the ones here https://github.com/Eric-Lennartson/pd-themes

edit nov. 4th 2021: fixed small bug & updated colorsgrey

That's great @seb-harmonik.ar
Here is a slightly updated and more complete version of my theme (I didn't post it before... ) colorsgrey-plugin.tcl.zip

OMG, it's very nice, great work! its much more easier, thanks your work!
one (actually two) more thing.
(1) I tried to make the menu bar to dark with the Info.plist file and it worked for a while but the next time when im tried to run Pd the UI was white again but the os appearance was dark... can anyone help with this specific thing?

to try this:
Open Pd/Content/Info.plist in TextEdit or any Plist editor (on mac) and replace the NSRequiresAquaSystemAppearance to look like this:

<key>NSRequiresAquaSystemAppearance</key>
<string>False</string>

It worked for me only one time here is the evidence:

The second thing is if this problem is already solved, how can i made pdwindow topbar to dark? Thx

@narcell native dark window manager stuff like topbars, buttons, dropdowns etc. being reflected was disabled because it created too much inconsistency. So dark mode as a whole was removed.

here's the commit: https://github.com/pure-data/pure-data/commit/1665a2ef341413f036251dfb88136223ca1fbf2c

(from the comment it seems like it's set to true in 2 places, the defaults file as well as the plist?)
though I'm successfully reading from some defaults to tell if darkmode is on here... idk

@narcell so looking at it a bit more, if you do want to mess with it you can try deleting the exec defaults write $::pd_guiprefs::domain NSRequiresAquaSystemAppearance -bool true line in pd_guiprefs.tcl.

Then you probably also have to delete the ~/Library/Preferences/org.puredata.pd.pd-gui.plist file, or at least delete the

<key>NSRequiresAquaSystemAppearance</key>
<true/>

in it

oh yes thank you! its dark now, i know now what 'inconsistency' you were talking about. its okay for now.
if I have the ability to do it I will try to find these bugs.
until then here is my color theme:
narcell-dark-plugin.tcl

@narcell ok I included it in the package, which I've moved fully to github

Pull Requests are the best way to submit themes for inclusion, if anyone else is interested

@seb-harmonik.ar tell me how did you make your plugin window to turn it black in dark mode?

and what do you think? is there any chance that the dark mode will not be disabled in the 0.52 version?

@narcell I wasn't aware the plugin window was black in dark mode. do you mean the console window background?

There is very little chance that dark mode will not be disabled in the 0.52 version. Getting it to look consistent is just too much trouble. You could try making a pull request for Pd to do that, though.

@seb-harmonik.ar Here is the plugin window that you made in dark mode:

And here is a "classic" Pd window in dark mode:

It looks like you solved the problem with the dark mod in your own plugin.
So your plugin is working correctly so there is something what is fixing the whole dark mode problem. I guess. What do you think?

@narcell I have no idea.
In addition, here on MacOs 10.14.6 mojave it doesn't look like that, even in dark mode the window is still light..

New release https://github.com/sebshader/pdnext/releases/tag/0.52-1

includes helpbrowser without limit to the number of panes (though there is sometimes flickering when navigating to new panes)

a tk event <<WindowClosing>> is now generated when windows are closed (probably not very useful to most)

also included are new colors:
atom_box_focus_outline - outline of gatoms with keyboard focus (defaults to black)
text_window_hl_text - color of highlighted text in [text] window
helpbrowser_hl_text - color of highlighted text in the help browser

https://github.com/sebshader/pdnext/releases/tag/0.52-2

added pdwindow_hl_text, color the text is highlighted in the pd console window

compiled a universal binary for mac intel x86_64 and arm64 (apple silicon m1 chips)

Found, and installed painlessly, this is really nice stuff here. !!

hjh

v. 0.53-1 has actually been ready for a bit, with a new graph_open color type (for opened GOP subpatches in the parent, currently a grey box)
unfortunately my macbook died and my new laptop isn't powerful enough to run VMs well I think (not macos anyway) and I had a lot of trouble cross-compiling wish.
So, windows and mac builds may take awhile.. unless someone else wants to build.. maybe I'll try to get some CI thing to make a release..
https://github.com/sebshader/pdnext/releases/tag/0.53-1

releases page has a windows build for 0.53-1 now

got a new release https://github.com/sebshader/pdnext/releases/tag/0.54-0
testing needed on macos

to try a version with jack linked you can try the artifact here https://github.com/sebshader/pdnext/actions/runs/5778432399