In Ubuntu 12.04 at least, there is such an option to configure the colour: CCSM > Ubuntu Unity Plugin > Experimental > Background Color
Just remember to set a high opacity (> 200) or the additive blending of the launcher will look ugly.
If you wish to return to the default behaviour of automatic colour section, just set Opacity=0.
In Ubuntu 12.04 at least, there is such an option to configure the colour:
CCSM > Ubuntu Unity Plugin > Experimental > Background Color
Just remember to set a high opacity (> 200) or the additive blending of the launcher will look ugly.
If you wish to return to the default behaviour of automatic colour section, just set Opacity=0.