My brain interprets Superman’s trunks as metallic/satin. Under certain artists like Jurgens, the chest logo looks metallic to me. Meanwhile, the cape and boots generally are NOT satin or metallic.
I don’t see how TAS Superman’s trunks or the blue bits of BTAS Batman get interpreted as anything OTHER THAN dark metallic colors. IMHO if you’re going to do the red stripe on black trunks with a TAS Superman toy, you might as well cel shade the whole figure, which would look cool IMHO.
But I’ve never seen any statue or figure or official real life costume go the satin/metallic route despite Superman’s trunks generally looking much higher contrast than the rest of his costume since the Golden Age.
Alex Ross even typically renders the fabric of the whole suit much like Reeve’s suit. Except when he makes the whole suit metallic.