Western Tanager (Piranga ludoviciana) Bright orange-red head, yellow body, black wings and back, found in western North America. Rufous Hummingbird (Selasphorus rufus) Small with an orange-rufous ...

The two-colour discs had different pairs of colours selected from an orange-to-red spectrum. This mirrors the colour range found in the male songbird beak. One idea was that the birds would be ...