Create GTalk themes

Steps to create a Google Talk Theme

1. Navigate to this folder;

C:\Documents and Settings\\Local Settings\
Application Data\Google\Google Talk\themes\system\chat

Here you can see all the pre-installed Chat themes.

2. Select a particular theme and click on the theme folder and navigate to this folder;

C:\Documents and Settings\\Local Settings\
Application Data\Google\Google Talk\themes\system\chat\\Contents\Resources

Here you can see main.css file. This is the file which defines the looks of Google Talk skins. You can edit these CSS and create your own custom theme. You can add your own custom images and colors to Google Talk.

3. Now open your Google Talk and select Settings-> Appearance and you will be able to see your new theme.

You can save these theme under different name and can also make it available for public download.


Source