Hi, Mark! I just discovered your comment and question. Please forgive me for my delayed response.

Yes, all three of those are complete sentences (independent clauses capable of standing alone as sentences–hear your voice drop at the end if you read them aloud!). But I discourage that construction because “as follows” or “the following” is a bit redundant with the colon, which expresses a similar thought. I would say, instead, “He picked four delicious shades of blue:” or “The colors he chose were an expression of his love for summer:” Both of these add to the reader’s understanding, whereas “the following” adds nothing. But *grammatically* you are on solid footing to use a colon after any of those constructions.

Thanks for writing!

He picked the following colors:
The colors he picked were the following:
The colors he picked were as follows:

Would you say that all three are complete sentences? I’ve been told the last two examples are not. Maybe you could address these examples in your article since they are very common occurrences.

Thanks.