The link I provided has this line:
fileTypes = ( 'sass' );
Looks like you should add:
fileTypes = ( 'sass', 'scss');
Also, I should have mentioned that the file is in JSON currently and ST2 expects XML. You can use AAAPackageDev to make this easier. The readme there explains how to do the conversion.
Last, you'll need a color scheme that supports the SASS scopes defined in the SASS.tmLanguage file you created.