gtk.css

/* /home/usr/.config/gtk-3.0 */

.thunar .standard-view .view {
	background-image:url("bg.jpg");
    background-size: cover;
    background-position: bottom right;
}

.thunar .standard-view .view * { background-image: none; }
.thunar .standard-view .view * { background: transparent; color: black; }

.thunar .sidebar .view { color: aquamarine; background: purple; }
.thunar .sidebar .view:not(:selected) { background-color: transparent;}
.thunar .sidebar .view:selected { background: transparent; border-left: 4px solid red; }
.thunar .sidebar { background-color: blue; }
.thunar statusbar { 
    background-color: red;
    margin: 0 -10px;
    padding: 0 4px;
    border-top: 1px solid yellow;
}