Single color alpha channels, like GIF images, will have grainy-looking rounded exterior edges compared to a properly built alpha-blended icon, such as the ones on the Google Toolbar or Internet Explorer itself.
If you don't want to just change the file in its respective template directory you can find the reference to the file in the document.
The path is "........\libraries\joomla\document\html\html.php".
PNG files are not supported directly since Windows does not natively support PNG files without linking in a lot of extra stuff.
The reason you need to use an alpha channel is because not everyone's toolbar background color is going to be the same gray, silver or beige that yours is set to.
(For example, the user can go to the search box with Alt-G, press the down arrow to pull down the search engine menu, then type "w" in the search box to select the "wikipedia" search engine.) Use The Google Toolbar also enables you to create a button to execute most any website's search engine using the term the user types into the toolbar search box.
The next two examples include a button to search the using the Wikipedia search engine, and another button to search the Internet using the Google search engine. It is possible for a web site to use form-encoded data instead of url-encoded data, and we do not currently support that.
To do this, add a search element in the form attribute in the search element. Also, it is possible to send CGI parameters and post data at the same time -- to do this, use two question mark '? This example uses a post method to send postdata (highlighted): The download URL you use to host the XML file for the button becomes the button's unique ID for updating the button.
If a second attempt is made to download a button from the same URL, the toolbar will offer only to replace the old one, not add a new one.
A custom button is a push button that you can add to the Google Toolbar that can have custom navigation, search, send and update capabilities.