California Gull californicus
| TABLE 1 | Herring Gull | Glaucous-winged Gull x Herring Gull | Glaucous-winged Gull | Glaucous-winged Gull x Western Gull | Western Gull |
| Mantle | very pale grey (Kodak 4-5) | pale grey (Kodak 5-6) | pale grey (Kodak 5-6) | pale grey to slate grey (Kodak 6-8) | slate grey (Kodak 8-9.5) |
| Tips of Primaries | jet black (Kodak 18-19) | blackish (Kodak 11.5- 16) | medium grey (Kodak 6-7) | blackish (Kodak 9-16) | black (Kodak 16-18) |
| Bill | yellow | pale greenish-yellow to fleshy-yellow | yellowish | pale greenish-yellow to orange-yellow | bright yellow to orange-yellow |
| Iris | pale lemon | pale lemon with dusky flecking to dull olive | dark brown to tawny | pale lemon to dusky | lemon whitish to dull olive |
| Orbital Ring | orange to yellow-orange | pinkish to yellowish (mixed) | pink | pinkish to yellow (mixed) | chrome yellow |