- Click Menu and select Terminal.
- Enter sudo cp -R /usr/share/themes/Mint-X ~/.themes/
- Enter pluma ~/.themes/Mint-X/gtk-2.0/Apps/panel.rc to open the file with the default text editor.
- Search for two instances of "Panel/panelbg.png"
- Comment out the two lines by placing a # at the beginning of the lines, for example: # bg_pixmap[NORMAL] = ...
- Save the file.
- Go to Menu > Applications > Preferences > Appearance, switch to the other theme and then back to the Mint-X theme.