How to copy to folder: /System/Library/Filters?
User-created Filters should be saved to /Users/yourUserName/Library/Filters. You may need to create this subfolder if it's not already present in your user Library.

Also, note that the easy way to edit or create a new Filter is to use ColorSync Utility. If you edit the file in a text editor and get invalid XML, it can bring down the whole QuartzFilter system.