The unclued lights become phrases, verifiable in Brewer, when their first (or, in one case, last) undefined word is added. One normal solution (also thematic in a way) includes the red and yellow names. Ignore all accents.

Across

1               Players or cast, cast out – literally (6)

7               Cyndi Lauper release with live backing in retail outlet (3,3)

13            Hemmed in France in your lean-to (5)

20            When fats are added, maybe infiltrates any organic cyanide (7)

21            Contribute old money for monitor lizard (6)

22            Poor Irene by day is a sea-nymph (6)

24            Lecture about marks on Latinized alloy (8)

26            The beak’s US money (4)

28            Yoko’s...