Reply To: Automatically insert space during typing

Ari’s solution was my next suggestion but i had to test a new possibility before i posted..

Although it is not possible to add characters automatically, this can still be automated using tracking. Again just as in my first post you will need to create a Character style. Though this time instead of creating a “no break” style, you will set only a tracking value of around 300 (this can be adjusted later to your liking.) In the paragraph styles options you will use the GREP Style to apply your tracking style to text: (?=\:).