Umicons offers KDE icons.
I'd like to extend my gratitude to mattahan, the creator of these beautiful icons, for giving permission to convert them for use with KDE. To further enhance the overall look, I've opted to use Window-Decoration and style "Plastik" for a slick and modern feel.
In terms of updates, Umicons are constantly updating, and the latest release brings in plenty of new icons, with over 700 different icons currently available. While many of these may not be utilized by KDE, it's still worth exploring the vast range of options. Furthermore, there are three wallpapers included, one of which was the same as the one used in my screenshots.
Overall, if you're in search of new icons for KDE and want to give your desktop a fresh new look, Umicons comes highly recommended.
Version 2.0: N/A