KDE developers continue preparing Plasma 6.6, and although there are over a month to go before the final stable release (scheduled for February 17, 2026), the team posts weekly updates on the KDE Blogs about what changes to expect from this version. After I covered some of them recently, now we have a new batch to look at.
One of the most notable recent additions is the ability to save the current visual configuration as a new global theme. Users can now capture their active color, window decoration, icon, and other appearance settings directly from System Settings, simplifying theme creation and reuse without manual component selection.
Oh these values get stored somewhere in I think either ~/.config or ~/.local I forget which one, so you can change them and check the file to see the code you it, but I have some examples here
https://github.com/Die4Ever/KDE-Windows-98-Theme/blob/main/look-and-feel/Reactionary98/contents/layouts/org.kde.plasma.desktop-layout.js#L23
Maybe you can use kfind to figure out the root file that has these values