Sometimes we want to change the theme of a single Component to use it in a very specific case, without changing the default theme of the Component. For example, in the application, we have greenish windows as part of the default theme, yet we want to display a red window in a particular situation. In other words, we want to use both windows in the application, but with a different theme.
Some Ext JS 4 Components have Sass mixins, which allow us to create new UIs. Some of these Components are panel, button, and window.
For example, we will create a new UI for the Window Component. The first step is to take a look at the file
appName/extjs/resources/themes/stylesheets/ext4/default/widgets/_window.scss. Open it and ...