Use a colon (:) at the end of a sentence to begin a list or text (this example is meta):
The war plane was painted three colors: red, white and blue
Capitalize the first letter of the word following a colon if it is a proper noun or begins a complete sentence:
She sent a message to her niece: Nancy, she said, there is a tsunami alert.
The implication was clear: They had to get to higher ground before the wave reached the coast.
But: They had two objectives: divide and conquer.
Use to introduce a long quote within a paragraph. Colons belong outside of quotation marks unless they are part of the quote.
Use colons for time of day (1:30 p.m., 12:45 a.m.), time elapsed (01:23:45) and legal citations (U.S. Code 5:552).
Part of a series on punctuation.