Kvantum VS Gradience

I'm using Kvantum engine with my custom Andromeda theme

I think Kvantum has support for theming both Qt6 and Qt5 apps now though so that might be worth trying if it bothers you that much.

The ones I know of are: Aurorae (built-in one), Kvantum (https://github.com/tsujan/Kvantum/tree/master/Kvantum) and Lightly (just a theme https://github.com/Luwx/Lightly). store.kde.org is down (at least I can't access it at the moment), so I've shared github links.

What about : https://github.com/tsujan/Kvantum ?

Make sure Kvantum is selected in the application style section of your look and feel settings. Read through the usage instructions on the Kvantum GitHub page.

Perhaps you can submit an issue

As for Kvantum, you'll need to either install it from your distro's repos if you're lucky, or if not you'll need to compile it yourself, you can check how to do that here.

arc-theme with kvantum look petty good imo.

It's written in QT, so you need a QT theme. There's the KvLibadwaita style for the Kvantum theme engine.

If your main problem with Adwaita are the colors, you can easily customize them, and there are even great GUI tools for this[1]

My issue with Breeze aren't the default colors, but rather the theme itself

[1]: https://github.com/GradienceTeam/Gradience

I really like GTK4 / Adwaita and dislike the look and feel of QT, but I guess that's just personal preference.

You can change the colors of Adwaita using https://github.com/GradienceTeam/Gradience it even has a mode to extract colors from your background like current android versions

Application Theme : adw-gtk-3 with Gradience

This might be an alternative for now - https://github.com/GradienceTeam/Gradience

if the app is using libadwaita you cannot modify the css, you can use gradience to set custom colours though, but it is not the same as modifying the css

For everything else I use the only tool available for properly configuring GNOME: dconf-editor. At this transitional time, managing themes is a challenge, but I like Gradience.

You could also use themix or Gradience

Try https://github.com/GradienceTeam/Gradience/ .

You've tried Nord from Gradience ?