Here is what I did to fix it. I only use VPN on the wired connection. I guess a similar approach will work for secure/VPN over wireless.
cd /usr/share/icons
# Make a copy of the existing icon theme
# "pvm" is me. Invent whatever name you like here
sudo cp -a elementary-xfce-dark pvm
cd pvm
# in index.theme, change the "Name=" field to something descriptive for you,
# e.g. "elementary Xubuntu dark - with nm-device-wired-secure"
sudo vi index.theme
# Optional step
# If you don't like the looks of panel/22/nm-device-wired-secure.svg, edit it.
# I made it lighter to fit the rest of the theme.
sudo chmod a+w panel/22/nm-device-wired-secure.svg
inkscape panel/22/nm-device-wired-secure.svg
Here is what I did to fix it. I only use VPN on the wired connection. I guess a similar approach will work for secure/VPN over wireless.
cd /usr/share/icons
# Make a copy of the existing icon theme xfce-dark pvm
# "pvm" is me. Invent whatever name you like here
sudo cp -a elementary-
cd pvm
# in index.theme, change the "Name=" field to something descriptive for you, wired-secure"
# e.g. "elementary Xubuntu dark - with nm-device-
sudo vi index.theme
sudo cp ../Humanity- Dark/status/ 22/nm-device- wired-secure. svg panel/22/
# Optional step nm-device- wired-secure. svg, edit it. nm-device- wired-secure. svg nm-device- wired-secure. svg
# If you don't like the looks of panel/22/
# I made it lighter to fit the rest of the theme.
sudo chmod a+w panel/22/
inkscape panel/22/
sudo gtk-update- icon-cache .