0 Change Font Type and Color of Panel Clock

The font type and color of the panel clock follow the windows text in a theme by default. In particular, if the font color is black and shown on a dark background through a transparent panel, you can't read the clock clearly, but you can tweak it by changing the font color. And you can define the font type for your panel clock as well.
The code in Step 1 below sets the font color to white and applies DS-Digital font (See  below), bold and size 16.

1. Open up the text editor Gedit and paste the following code:
   style "my-panel-clock"
   {
   fg[NORMAL] = "#FFFFFF"
   font_name = "DS-Digital Bold 16"
   }
   widget "*.clock-applet-button.*" style "my-panel-clock"
2. Save the file as .gtkrc-2.0 (including the dot in front of the filename) inside your home directory /home/your_user_name.
3. Log out and log back in (OR enter killall gnome-panel into the Terminal) to see the change.

   The DS-Digital font can be downloaded here. After downloading, unzip the file and install the font into the system for use. See Install Extra Fonts.
   The filename leading by a dot represents it's a hidden file and visible by toggling the key Ctrl-H in the Nautilus file browser.