Wrong default syntax highlighting in sublime text 3
Solution 1:
Changing the syntax highlighting for any file type is easy in Sublime. Simply open a file with the extension you want to change, then click on View -> Syntax -> Open all with current extension as... and choose whichever language you wish. This will add the current extension to the "extensions" list in Packages/User/LanguageName.sublime-settings, where LanguageName is the syntax you chose, such as HTML in this case.