bei mir klappt es so.
wein nur nicht ob es richtig ist.
CSS
/* Playlist - wenn mit Maus */
ytd-playlist-panel-video-renderer[watch-color-update][can-reorder]:hover.dragging,
ytd-playlist-panel-video-renderer[watch-color-update][can-reorder].dragging,
ytd-playlist-panel-video-renderer[watch-color-update]:hover:not(.dragging) {
background-color: rgba(98, 0, 164, 0.1) !important; /* Purple 70 */
}
/* Playlist - wenn Markiert */
ytd-playlist-panel-video-renderer[selected][watch-color-update] {
background-color: rgba(98, 0, 164, 0.1) !important;
}