This has been bothering me for a while. Its an aesthetic issue. The dropbox icon on the toolbar (rox-icewm) has a black background that clashes with the grey color of the toolbar. This is strange since the icon itself has a transparent background (~/.dropbox-dist/dropbox-lnx.x86_64-123.4.4832/images/hicolor/16×16/status/dropboxstatus-idle.png). Any idea of how to fix this? Short of changing the image itself (which is only a short term solution as Dropbox replaces the icon images with the original every now and then).