Is it possible to change panel color?

[Xiong Jiang]

Hi all,

Thanks for the terrific XFce4.2rc1 and xcompmgr. It's great to see
transparent panel on my screen. I am just wondering if it is possible
or will be possible to change the color of the panel to other solid
color?  Different color with transparency could match the desktop
background pictures much better. For example I personally like a dark
green color for the panel :)

Thanks!

Shawn