Matcha-gtk-theme VS arc-theme

I use one of the Matcha themes with a few modifications and the Qogir icons.

Your other option is to find a theme that has a slimmer look, that way you don't have to change the font size or anything else and let the theme take care of the padding. This theme comes to mind, although I haven't personally used it in a while. There's also Linux Mint's official theme Mint-Y, it might be in Pop!_OS's repositories (sudo apt install mint-themes) but there was a recent update that made the themes look much better, I'm unsure if this new update is already in the repos.

Matcha as well.

I use Matcha on just about every system. https://github.com/vinceliuice/Matcha-gtk-theme

You can write an issue/ask a question here. It's based on the original theme, which is not active since 2017, so I guess the packages in Linux distros are built from that fork.

The theme on this picture is Arc

arc-theme with kvantum look petty good imo.

Me just being lazy instead of looking for it myself...how does this work? For example, let's say I want to use the Arc Dark theme on F36/Gnome 42. The theme claims it includes a GTK4 variant (btw, Fedora uses this fork of the Arc theme according to the rpm spec, as the original has been unmaintained for some time). How do I tell Gnome 42 libadwaita apps to use the Dark Arc theme? If it's an export line in my .profile file, then I must have done something wrong, because that didn't work for me. What is this trickery you mention, please do tell!

If your theme is already configured for libadwaita, it should be possible to use it in place of the default Adwaita by overriding the GTK_THEME variable globally or for each application via *.desktop files. For example, to globally set Arc-Dark (from the Arc theme), add GTK_THEME=Arc-Dark to a config file in $HOME/.config/environment.d for Wayland sessions or $HOME/.xprofile for X11.

I'm using the arc-theme, however because almost every native GNOME app is being ported to libadwaita, it doesn't make really sense anymore to offer custom theme support.

I have been using arc-theme for close to 5 years and even when primary author moved on, it seems to be working well enough via jnsh fork (https://github.com/jnsh/arc-theme). Has gnome authors ever considered adopting an existing theme vs building something from scratch?

I just upgraded upgraded from 18.04 LTS to 20.04 LTS and my topbar theme is a mix of light and dark, I've been using the "arc-dark" theme. I'm not a linux expert..been using it as workstations at home for a few years... perhaps it is due the theme not being compatible anymore as I found a fork here "https://github.com/jnsh/arc-theme"

Ubuntu 20.04 GNOME Shell 3.36.9 Theme link: https://github.com/jnsh/arc-theme

Arc doesn't support GTK4 yet (Extensions app).