Grammatically Correct: The writer's essential guide to punctuation ...

GRAMMATICALLY CORRECT
SEPARATING A CHARACTER'S NAME FROM HIS
OR HER LINES IN SCRIPTS AND SCREENPLAYS
Alternatively, a period may be used, or the character's name may
appear on a separate line.
COLON OR SEMICOLON?
Some writers are confused by the distinction between the colon and
the semicolon, and in fairness, there are a few cases where either
mark might do. How do you decide which one to use, then? It
depends on context and tone. The colon is a "stronger" mark, one
that increases the emphasis of what is being said. Consider the
difference in nuance between the following two sentences:
Time was ticking away; he had to make a decision soon.
Time was ticking away: He had to make a decision soon.
In both examples, the connection between the two items of information
is clear, but the second one suggests a bit more urgency to
the situation. Thus, the context would determine which mark is the
most appropriate.
Note that a choice between these marks could arise only in situations
involving their subtler roles-those having to do with emphasizing
relationships. In the majority of cases, the roles are distinct, with
no overlap. The semicolon is the only mark that is appropriate
when you need to separate elements that wouldn't be sufficiently
distinguished if commas were used, and the colon is the only mark
that is appropriate when you need to separate a lead-in or introductory
part of a sentence from what follows.
STYLE CONVENTIONS
• You may leave either one or two spaces following a colon. Just
be consistent.
• When a colon follows quoted text, place it after the closing
quotation mark. (See page 182.)
• If the text immediately preceding a colon is italicized, italicize
the colon as well.
104