The Skidmore Guide to Writing
Use a colon at the end of an independent clause to introduce a list, an explanation
of the clause, or an example:
There are many interesting things in Billy's closet: old shoes, fluffy pompoms, and
hundreds of baseball cards.
Don't use a colon after a verb or a phrase like "such as" or "consisting of" or after
a form of "to be" (am, is, are, was, were).
Click here to read more about colons in the context of correct grammar.