Unity Launcher Background Colour

[Grizzly]

Hi

Having an issue with "Unity Launcher Background Colour" after upgrading to 
Plucky (it was "probably" the same on Oricular and Noble)

The launcher background colour has always being "odd" but as I have different 
wallpapers on each version (my own not the repo ones) I hadn't made a 
connection before

After Plucky was set-up I noticed the background colour was not as I had set in 
appearance (Black), this seems to not only effect Launcher but other dialogues 
also, I then took a run at Unity-Tweak-Tool, (almost) all changes seem to take 
effect as they are changed, BUT changing Launcher Background Colour from
"Based on Wallpaper" to "Custom (Black)" has no effect, even after login off / 
on, rebooting or a cold restart

With custom set, changing wallpaper still alters the Launcher Background Colour 
to an average(?) of the wallpaper colour

any work-arounds or config files that "may" do what tweak tool should do??

Thanks 

Grizz