Customize Firefox Toolbars with Images

Customizing the toolbars with pictures is very easy, because Firefox is an open software. You can use an image on the internet to do this.

Steps

Get the Firefox add-on called AnyColor. Your theme appearance for Firefox has to be the default skin for this add-on to work.
- Set the options for the add-on, to your preferences, but don't change the preset just yet, since we are going to make a custom one.
Make a picture that matches the dimensions of the toolbar (tab bar excluded)
- You don't have the correct size. In the options, you can specify what part of the picture to use.
Go to options of the add-on.
Make a new preset.
Go to the appearance tab, and in the "Header" section, select your image. This can be an "url" or a offline file. You can also change the footer in the footer section.
Choose other options and press OK.
Enjoy your new toolbar appearance!

Creativity is the key.
Designing your toolbar picture might take some test and tries.
Just check the checkbox to use a HTML script. In the HTML script, you might want to add some javascript.