Do you want to restore your speakers?
Or do you want to save money?
The 250ti Jubilee tweeters can only be replaced completely. No dias available.
The tweeters are expensive.
Another option is to buy nice looking ebay spares as most here do. Problem is that you can't see the inside of these ebay "bargains". You will probably end again looking for tweeters when the ebay stuff is finally coocked.
Whatever...
You can replace them with 035Tis. Don't worry about the colour. It does nothing with the sound. A jubilee with 035Tis is no longer a jubilee though.
Oh, the 035Tis are also expensive.
But then there is ebay....