Is a colon necessary after the phrase "some of these include"?

“When the introduction is not a complete sentence and one or more of the items of the list are needed to complete it, no colon or dash should be used” (Words into Type, 3rd Edition, Prentice-Hall, Englewood Cliffs, NJ, 1974, p. 181). “Some of these included” is not a sentence, and the items art and class are needed to complete it (that is, make it into a sentence), so there should not be a colon after included. Also, include indicates that what follows is “part of a whole or group” (Merriam-Webster online, https://www.merriam-webster.com/dictionary/include), so “some of these included” is redundant. “Some of these were” would be better.