in .tmTheme files the scope key defines how a element is highlighted:
name
HTML: Attribute
There are a couple of sublime text packages you can use to do this.
Go to https://sublime.wbond.net/ and click "Installation" and follow the instructions to install sublime text package manager.
I know of a couple of sublime text packages which display the current scope in the status bar.
To install a package with sublime text package manager open sublime text's command palette (ctrl+shift+p
) and choose the command Package Control: Install Package
and then select one of the above packages.