These two forms of punctuation are often underused — or used incorrectly — but they can add color to your writing: the dash and the colon.

(Do you see what I did there?)

Imagine a picture of a rainbow in black and white. The shape of it remains, likely with varying shades of gray, but it’s not nearly as pleasing to look at without all the contrasting colors. Think of writing as a rainbow: even if we begin with a solid concept, without varying sentence structure or using different forms of punctuation, we take the color out of our work.

Though often misunderstood and underused, the colon and the dash represent the boldest colors of the rainbow — each emphasizing our brilliant ideas in different ways. These punctuations are highly effective, and they are easier to use than most people think.

The colon

Colons allow you to do two main things: introduce additional information, such as lists, and expand on ideas.

Use a colon to introduce additional information, such as lists.

While colons often introduce lists, understanding them in only that way leads to misuse. You can’t just use a colon every time you have a list, as in three foods I hate are: clams, mashed potatoes, and cottage cheese. This statement is 100% true (I really do despise these foods) but 100% grammatically incorrect.

To use a colon correctly, it must be proceeded by a complete sentence. I can fix the grammatical error above by rewording my thought to include a complete sentence before my list.


  • I hate three foods: clams, mashed potatoes, and cottage cheese.
  • There are three foods I absolutely hate: clams, mashed potatoes, and cottage cheese.

Use a colon to expand on ideas.

Colons are helpful when we want to elaborate on an idea or clarify a thought. Again, a full sentence must precede it, but then an explanation will follow.


  • I hate mashed potatoes: they have a mealy texture, and they taste like paste.
  • A rainbow may seem like magic, but its magic is rooted in physics: when the sun passes through water droplets, light is refracted into seven different colors.

Think of a colon as a gateway to the next piece of information. This way, you can follow a formula:

Full sentence + gateway = complete thought.

“I hate three foods” is a full sentence. When readers open the gate, they see which three foods.

“I hate mashed potatoes” is a full sentence. When readers open the gate, they see why.

The dash

While colons tend to be more understated, dashes are bold — placing emphasis on certain ideas or interrupting a train of thought. Dashes are also a bit more versatile, as they don’t always need to be preceded by a full sentence.

I like to think of the dash as my Aunt Kim, who comes to Easter dinner in a full bunny costume, after coordinating the largest egg hunt in the neighborhood. When she steps onto the front lawn as the Easter bunny, everyone stops eating and talking to turn their attention toward her. As with my Aunt Kim, a dash calls for attention.

Kim and kids, just before a big Easter egg hunt (photo provided by Jessica Lucia)

Use a dash to emphasize something specific about a preceding idea.


  • I find mashed potatoes disgusting — an unpopular opinion among most people.
  • Rainbows are often a symbol of hope — representing peace and unity.

Similarly, use a dash to set off a surprising element to a preceding idea.


  • When I arrived at my aunt’s for Easter, I was shocked by what I saw — a woman in a bunny suit surrounded by hundreds of colored eggs.
  • Once the storm subsided, I looked out the window in amazement — the clouds had parted as a double rainbow graced the sky.

Use dashes to interrupt a thought, placing emphasis on the information that comes between them.


  • The alarm — buzzing like an angry bee — startled me out of a sound sleep.
  • Pandas — though seemingly cuddly and loveable — are solitary animals and prefer to be left alone.

Time to experiment

Writing in black and white may get your basic message across, but writing in color captures your readers’ attention and calls on their imagination.

While colons and dashes lose their effect if overused, incorporating them skillfully emphasizes certain ideas—adding bold splashes of color to your work.

Mother. English Instructor. Runner. I love the New York Mets, bridges terrify me, and I hate cottage cheese.

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store