Mister Micawber was kind enough to give me hand with this question a couple of days ago, but we both needed a Brit to confirm whether there are caps after colons in BrE, and when does this rule apply.

Here are some examples of what I'm having trouble with:

1.) The wind proposed a contest, and when it saw an old man walking on the road, it stipulated the conditions: whoever manages to undress the man, wins.

2.) The teacher came to a surprising discovery: the best salesmen are the ones with the most developed sexual instinct.

3.) To clarify: The undeniable force of the wind was what launched the object into the afore mentioned area.

4.) ... this means: If you can think and dream, you can listen.

I found several examples on this site (in the forums) that do not use caps after colons and no examples of caps after colons (except with names, abreveations, ...). Is that just AmE?

I know quotations fit the bill (as it were) of caps after colon, (i.e. Wayne: "Get lost!") but as far as everything else goes, I'm lost.
Do not use a cap. - unless a company's house style requires it.
Just follow standard rules for capitalization: no need per se after the colon.
Students: Are you brave enough to let our tutors analyse your pronunciation?
Thanks guys.

Got so many different views on this, I was completely lost!
Students: We have free audio pronunciation exercises.