If you are using the “vitualmin framed theme” (virtual-server-theme-9.5.wbt.gz) then the file
should look like this
i noticed the update added come colors to some lines.
For other themes i don’t know. You could compare the /etc/webmin/“used-theme-name”/config file with one from a backup.
To beat the question, why i am not using the new theme: i did for a while, but the default color went from a nice dark blue to a very ugly, very bright blue and the dark blue isn’t even in the presets anymore. After having wasted a few hours trying to get the color right again, i switched back and got on with more important things.
hope this helps