Go to /Applications/MySQLWorkbench.app/Contents/Resources/data/code_editor.xml (to open the contents of the app right click on the workbench app and select 'Show Package Contents')
Open code_editor.xml
Paste the code you've selected before inside the tag <language name="SCLEX_MYSQL">, replacing all styles in that tag
Using Mac
copy.xml
file/Applications/MySQLWorkbench.app/Contents/Resources/data/code_editor.xml
(to open the contents of the app right click on the workbench app and select 'Show Package Contents')code_editor.xml
<language name="SCLEX_MYSQL">
, replacing all styles in that tag