Conspicuousness and toxicity may be inversely related, as polymorphic poison dart frogs that are less conspicuous are more toxic than the brightest and most conspicuous species. Energetic costs of producing toxins and bright color pigments lead to potential trade-offs between toxicity and bright coloration, and prey with strong secondary defenses have less to gain from costly signaling. Therefore, prey populations that are more toxic are predicted to manifest less bright signals, opposing the classical view that increased conspicuousness always evolves with increased toxicity.