This is a nord theme for qBittorrent based on the nord colour palette and is a fork of Mahdi Mirzade's themes with only the colours changed.
The theme can be installed by downloading the nord.qbtheme file from the releases page and importing it into qBittorrent.
The qbtheme file can also be compiled with rcc src/nord.qrc -o nord.qbtheme --binary.
In qBittorrent, go to Tools -> Preferences -> Behaviour -> Interface -> UI Theme file and select the nord.qbtheme file.