Color Involutions in Graded Algebras: Representability Theorems and Specht Property

Abstract Let G be a finite abelian group and let A be a G -graded algebra with color involution $$*.$$ ∗ . We first establish a Wedderburn–Malcev decomposition in case A is finite-dimensional. Then, we prove several results for algebras with polynomial identities in this setting, including the Hook theorem, the Specht property, and, most notably, the Representability theorems. The latter assert that A satisfies the same $$*$$ ∗ -identities as the Grassmann envelope of a finite-dimensional $$(G\times \mathbb {Z}_2)$$ ( G × Z 2 ) -graded algebra B with a suitable color involution $$\sharp $$ ♯ related to $$*$$ ∗ .