I'm new so let me introduce myself, I'm MysticalBurrito and I have been using ubuntu for several years now, I specialize in wallpaper design and just recently have been tinkering around with themes.

I figured out how to make your default Unity panel look different.
Please note I am still investigating this so not everything is actually working yet. just give me some time and A more complete and thorough tutorial will come out.

Okay, lets get started. Open your terminal and type the command

Code:
gksudo nautilus
enter your password then navigate to /user/share and look for the folders

unity unity-2d and unity-greeter
Copy those to your desktop but leave nautilus open, you will need it later
Inside you will finde the files needed to retheme your Unity.

Edit them and then just copy them back to /usr/share and log out and then back in and viola! your unity panel is rethemed.

Heres an example one I have made, although Its not quite finished yet.
(Note: it may or may not work depending on your screen resolution and unity settings.)

Download

If your settings are supported your desktop should look like this: