Kvantum is a theme engine for Qt-based applications (used by KDE, LXQt, etc.). It enables highly customizable and modern-looking themes, particularly matching GTK apps and KDE apps together.
It does not theme your whole desktop, but rather Qt applications’ appearance—buttons, menus, scrollbars, etc.
🧠 How do KDE themes work?
There are 4 key components to KDE’s look:
ComponentAffectsExample DirectoryPlasma ThemePanel, widgets, system UI~/.local/share/plasma/desktoptheme/Application StyleButtons, menus, scrollb,rders~/.local/share/aurorae/themes/
Color SchemeApp background, text colors~/.local/share/color-schemes/