Here are a few statistics:
- Excluding those required for URL schemes, my published posts contain 121 colons.
- 59 of those colons are segmental.
- I'm also fond of syntactical-descriptive colons, sprinkling them in 34 times.
- 11 appear to be syntactical-deductive.
- A mere two denote subtitles, while only one seems to be appositive.
- Evidently I've picked up on the Internet style of what article author Conor J. Dillon calls "jumper colons." I cannot classify the remaining 14 uses in any other way: they all follow dependent clauses, and that's the end of their similarity to one another.
(For the definitions of these usages, see the Wikipedia entry on Colons (punctuation).)
As my tentative phrasing suggests, I'm not convinced I got the breakdown completely right. The distinctions between syntactical-deductive, syntactical-descriptive and appositive are not at all clear to me.
The mere thought of using a colon now fills me with dread. Need proof? Prior to reading the first-mentioned piece, I'd have made the previous paragraph a single sentence, with a colon following "right."