I'm using Zukitre (but Zukitwo have the same problem) with XFCE and it looks great, however, in some applications the side panel colour is white instead of light grey. In Thunar, it just doesn't look as good as Nautilus (like this screenshot of Firefox download window that uses GTK3, but Catfish, for example, looks buggy with grey text between white space.
I'm using Zukitre (but Zukitwo have the same problem) with XFCE and it looks great, however, in some applications the side panel colour is white instead of light grey. In Thunar, it just doesn't look as good as Nautilus (like this screenshot of Firefox download window that uses GTK3, but Catfish, for example, looks buggy with grey text between white space.