Foreground text color when panel is black

[Marc MAURICE]

> Maybe using custom gtkrc. I don't much about it specifically, but you 
> may find some inspiration in existing themes, like:
> https://github.com/shimmerproject/Greybird/blob/master/gtk-2.0/apps/xfce-panel.rc 
>
Thanks !

A simple .gtkrc-2.0 did the trick :

$ cat ~/.gtkrc-2.0
style "fgwhite"
{
     fg[NORMAL] = "#ffffff"
}

widget "*Xfce*Panel*" style "fgwhite"