They are not dull. rewrite beginning with dull

Dull they are not.

Explanation:

To place emphasis on the adjective, you place it at the beginning of the sentence. The same pattern is used by Pamela Lutwyche in the title of her poem "Easy It Was Not."

When the sentence is positive, the inversion pattern requires putting the verb before the subject:

e. g. Blessed are the pure in heart.

Tender is the Night.