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~/.kde/share/apps/desktoptheme/
[This path is for Plasma Themes]
Your theme is a QT curve style, go to System Settings > Application Appearance > Style then where it says Widget Style, select qtcurve from the dropdown list, then click apply. You can import your qtcurve theme and configure it by clicking on the "Configure" button next it.
You must install QTcurve first with sudo apt-get install qtcurve
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