Download : MateGreenPlankTheme.tar.gz
I have made a small theme for Plank in Ubuntu Mate green.
I think it looks better than the grey default background of Plank.
This is the default Plank theme in Ubuntu Mate 16.04 Xenial Xerus.
Compositing should be activated.
Download and unpack MateGreenPlankTheme.tar.gz (Right click in caja -> extract here)
Open the extracted folder MateGreenPlankTheme.
Open a terminal in the MateGreenPlankTheme folder.
Copy and paste the two commands from install.txt or here to the terminal and press enter (you must enter your password):
sudo tar zxf MateGreen.tar.gz -C /usr/share/plank/themes sudo chmod -R 755 /usr/share/plank/themes/MateGreen
You can also extract the second tar.gz and copy the containing folder MateGreen to /usr/share/plank/themes and give the right permissions with caja.
Click on Plank preferences and choose MateGreen theme.