punctuation - Interchangeability of "—" (dash) and ":" (colon)

Let me cite two examples, one using "—" (dash) and the other using ":" (colon):

John has three sisters — Sita, Mita and Rita.

John has three sisters: Sita, Mita and Rita.

Grammatically, both sentences are correct. The only issue here is the use of two different punctuation marks as one sentence uses "—" (dash) and the other ":" (colon).

Which punctuation mark is correct? What is scope of usage of each of the punctuation marks? Can they be used interchangeably in the given context?

I am not going into the issue of m-dash or n-dash; nor am I concerned how a "—" (dash), when occurring in a pair, is to be used.

Can anyone shed some light?

Answer

Probably mostly a matter of preference. I myself have slight preference for a simple comma over "--". And a larger preference for "--" over ":". The dash to me signifies a space of time, almost a breath if it were spoken. The colon to me has a "scientific" highfalutin feel, similar to "to wit".