"Layer Control"? You mean the Toolbar-control element? Thats just for "real" toolbars, the old graphic user interface,
so it isn't possible.
But why not using the old toolbars, they are available, work well (accepts the icon color issue, they not change the background color by color scheme and the background isn't transparency. Not beautiful, but working).
command: _-TOOLBAR
Werkzeugkastennamen eingeben oder [ALLE]: LAYER
Option eingeben [Anzeigen/AUsblenden/Links/Rechts/Oben/Unten/VERSchiebbar] <Anzeigen>: _show
If you don't like to dock the toolbar and not like to place them outside the program window,
you can also place them hovering the titlebar or the ribbon. How to so: Place them by drag&drop while you hold the [CTRL] Key down!