Originally Posted by Steven Lake
"Hanging above them were two moons; one red, one blue." This sentence has better flow than saying, "Hanging above them were two moons. One was red, one was blue." or even simply replacing the semi-colon or period with a comma as it elicits a different, and ultimately more fluid kind of "pause" than either of the other viable punctuation choices would.
I would have used an em-dash instead in that example.